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Curcuma species as elements in traditional Chinese medicines play important roles in anti-inflammatory, antimicrobial, antirheumatic and antiviral activities. The bioactivities of ethanol extracts of 12 Curcuma species rhizomes were explored in this study. Most of these ethanol extracts showed excellent antioxidant activities, and the C. sichuanensis extracts (0.66 μM TE/mg EE) exhibited the best activities. These extracts not only had good antimicrobial activity against gram-negative bacteria (C. kwangsiensis var. nanlingensis, MIC=275.65 μg/ml), gram-positive bacteria (C. phaeocaulis, MIC=285. 52 μg/ml) and fungus (C. longa, MIC=80.87 μg/ml), but also revealed anti-inflammatory activities (C. aromatica, 42.6% inhibition at 100 mg/kg) suppressing the expression of TPA-stimulated inflammatory cytokines, COX-2 and TNF-α. Consequently, some Curcuma species can be used as natural antioxidants, antimicrobial or anti-inflammatory agents in functional foods, pharmaceuticals and cosmetics.

In this paper, a methodology for designing a distributed model for coplanar asymmetry transformer on gallium nitride (GaN) process is proposed, which can accurately characterize the transformer’s feature up to a millimeter-wave band. The paper analyses a transformer-based matching circuit and proposes a practical transformer design procedure. A two stage, transformer matching based X-band power amplifier (PA) is reported here. Using the proposed transformer model and correlated transformer design procedure can sharply reduce schematic design period and optimum process time. The PA chip is designed on a 0.25 µm GaN technology process and occupies a 1.515 mm2 area. At a 28 V supply, the gain and output power of the PA reaches 15 dB and 29 dBm respectively, and the wideband matching transformer reaches 47.6% bandwidth. To the best of our knowledge, the distributed model for coplanar asymmetry transformer and transformer-based X-band MMIC PA on GaN process in this work is the first case among the reported papers.

This paper presents a GaAs-based Ka-band low noise amplifier (LNA) with gain flatness enhancement. Active device optimization and inductive degeneration techniques were employed to obtain a low noise figure (NF) and good input/output return loss. In order to achieve a flat gain response over a wide bandwidth, the stagger tuning technique was utilized. The proposed LNA was implemented by 0.15 μm GaAs pHEMT process, and the chip area is only 1.5 × 0.9 mm2. Measurement results show that the presented LNA exhibits a small signal gain of 21.5 ± 0.3 dB, and the NF of the LNA is less than 2.2 dB from 32 to 40 GHz at room temperature.

Cedrus deodara is a cedar plant from the Pinaceae family. Because Cedrus is widely used in health care products, cosmetics, medicine, and insecticides, the essential oils of Cedrus deodara (CDEOs) ...

Severe skin injuries are hard to repair and susceptible to bacterial infection. Development of a versatile antimicrobial anti-inflammatory hydrogel dressing that eliminates concern over antibiotic resistance is urgently needed but remains an elusive goal. Our research, described herein, the design and fabrication of a new family of supramolecular hydrogels based on hydroxypropyl chitosan (HPCS) and poly(N-isopropylacrylamide) (PNIPAM) may prove to be that goal. Employing the reversible cross-linking by β-cyclodextrin (β-CD) and adamantyl (AD) pre-assembly, the hydrogels can be formed in a facile one-pot method. Additionally, the structure and performance of the hydrogels can be controlled by a simple adjustment of the AD content. The obtained hydrogels exhibit an abundance of desired properties; they are injectable, thermosensitive, highly ductile, self-healable (will self-heal recurring damage to the hydrogel bandage of up to several millimeters wide), biocompatible, and have antimicrobial activity against Staphylococcus aureus when infused with dipotassium glycyrrhizinate (DG). Using a mouse full-thickness skin defect model, in vivo wound healing evaluations revealed that the DG-loaded hydrogels (HP-3/DG10) applied to the wound resulted in rapid wound closure. The hydrogels promoted efficient tissue remolding, collagen deposition, decreased inflammation and performed better than the control groups of commercial Tegaderm

Essential oils isolated from the Lamiaceae species are attracting increasing interest because of their applications in natural food preservation and pharmaceutics. The aim of this study was to systematically investigate the composition and biological effects of six Lamiaceae essential oils. Approximately 106 components were identified by gas chromatography-mass spectrometry (GC–MS), and the predominant compounds were linalool (0.05–46.55%), α-pinene (0.12–45.35%), o-cymene (0.91–41.20%), patchouli alcohol (28.27%), dl -menthol (21.12%), isobornyl acetate (22.52%), d -limonene (0.01–18.42%), α-terpineol (0.07–4.88%), and β-pinene (0.08–2.03%). Most of these essential oils were found to have effective antioxidant activities (IC50; 1.07–18.77%), as estimated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging assays. The essential oils not only had antibacterial activities (6.5–12.3 mm diameter inhibition zones), but also had antifungal activities (6.5–19.0 mm diameter inhibition zones). The essential oils exhibited strong anti-inflammatory activities and markedly decreased the production of tumor necrosis factor (TNF-α), nuclear factor-kappa B (NF-κB), interleukin 6 (IL-6), and cyclooxygenase 2 (COX-2). The most abundant compounds in the essential oils isolated from the six Lamiaceae species have potential applications in the scavenging of free radicals, inhibition of bacterial and fungal growth, and relief from inflammation.

This paper proposes a 110% relative bandwidth (RBW) low-noise amplifier (LNA) for broadband receivers with flat gain, low noise and high linearity. Bias and parasitic parameters derived wide bandpass (BPDWB) matching networks and a cascode with dual feedbacks are introduced for broadband performance. Matching network design procedures are demonstrated, and results show that the frequency response of the network fits the target impedance well from 1 GHz to 3.5 GHz. The proposed BPDWB network improves the design efficiency and enhances the prediction accuracy of impedance matching. The proposed LNA in 0.25 μm GaAs pseudomorphic high electron mobility transistor (GaAs pHEMT) technology realizes a minimum NF of 0.45 dB at 1.6 GHz where the NF is less than 0.55 dB within the operating frequency band. A flat gain of 22.5–25.2 dB is achieved with the input voltage standing wave ratio (VSWR) below 1.22 and output VSWR less than 2.5. In addition, the proposed LNA has good linearity where the output third-order intercept point (OIP3) is better than +31.5 dBm, and the output 1 dB compression point (OP1dB) is better than +19 dBm over the wide frequency range.

This paper presents a broadband GaN pseudo high-electron-mobility transistor (pHEMT) two-stage driver amplifier based on an enhanced feedback technique for a wideband system. Through well-designed parameter values of the feedback and the matching structure of the circuit, a relatively flat frequency response was obtained over a wide frequency band. Simultaneously, in order to reduce the fluctuation of current caused by the environmental temperature, a bias circuit with quiescent current temperature compensation was designed. The driver power amplifier, which was implemented in the form of a monolithic microwave integrated circuit (MMIC), was designed to drive a broadband high-power amplifier. The designed broadband driver amplifier for the 6 GHz to 20 GHz frequency band had a very small die size of 1.5 × 1.2 mm2 due to the use of an optimized impedance matching structure. It exhibited a small-signal gain of 12.5 dB and output power of 26 dBm. The flatness of this driver amplifier for gain and output power was achieved as ±2.5 dB and ±1 dB over the entire frequency band, respectively. The experimental results showed up to 35 dBm in the OIP3, and the current variation range was ±5 mA after using the temperature compensation bias circuit.

The long noncoding (lnc) RNA MIR4435-2HG is known to promote lung cancer; however, its role in prostate carcinoma (PCa) remains unknown. The aim of the current study was therefore to investigate the role of MIR4435-2HG in PCa by detecting differential gene expression using quantitative PCR and ELISA kits. Furthermore, overexpression experiments were performed to analyze gene interactions and Transwell assays were used to analyze cell invasion and migration. The present study demonstrated that plasma levels of MIR4435-2HG and transforming growth factor-β1 (TGF-β1) were significantly higher in patients with PCa compared with healthy controls. Furthermore, MIR4435-2HG and TGF-β1 plasma levels were positively correlated in patients with PCa, but not in healthy controls. The results from the follow-up study suggested that MIR4435-2HG was closely associated with patient survival. MIR4435-2HG overexpression and treatment with TGF-β1 promoted cancer cell invasion and migration. In addition, TGF-β inhibitor attenuated the enhancing effects of MIR4435-2HG overexpression on cell invasion and migration. MIR4435-2HG overexpression led to upregulation of TGF-β1 expression, whereas TGF-β1 treatment had no effect on MIR4435-2HG expression. These results suggested that MIR4435-2HG may promote PCa by upregulating TGF-β1.

In this paper, a design of Ka-band monolithic microwave integrated circuit (MMIC) power amplifier (PA) in 0.15μm E-mode GaAs pHEMT process is presented. The PA is co-design with thermal analysis to enhance heat dissipation ability. Simulation result shows that, the PA exhibits 29dB of power gain, 32.4 dBm saturated output power (Psat) and more than 27.5% power added efficiency (PAE) from 34 GHz to 36GHz. The input return loss is lower than −18dB, and the output return loss is lower than −13.5dB. The PA maximum channel temperature can be lower than 114.9°C for 80°C MMIC backside. The PA is biased at VD of 3.7V and Vb of 0.6V. The total chip area is 4.2*2.2 mm2

This Influence on the echoes of the chaff cloud by the translation and rotation of chaffs are studied according to the chaff spiral descent model. The characteristics of the frequency spectra and polarization of the chaff cloud are studied using the statistic method. Firstly, the spiral descent model of the chaff cloud is introduced, as well as the polarization scattering matrix of the rotation dipoles. Then, the self-correlation functions and cross-correlation functions of the elements of scattering matrix of the chaff cloud are analyzed, presenting the power spectra and cross power spectra of the elements of scattering matrix. Finally, the numerical results are given when the orientations of chaffs obey the uniform distribution and horizontal distribution.

Essential oil of herbs has natural bioactivity, which can be applied on biomedical products, pharmaceutical preparations, natural functional nutrition and cosmetic additives. The chemical components and bioactivities of essential oils extracted from Alpinia officinarum Hance rhizomes collected from ten various habitats in China were comparatively investigated. The yield of ten essential oils varied from 0.93% to 4.35%. In total, 53 components were identified from GC–MS analysis, and the dominant compositions were 1,8-cineole (0.15–13.77%), α-farnesene (0.11–7.93%), γ-cadinene (2.30–6.95%), α-terpineol (0.28–5.67%), α-bergamotene (1.88–15.69%) and globulol (0.95–3.16%). The vast majority of these essential oils revealed outstanding anti-bacterial activities, especially against Gram-positive bacteria. According to 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mice ear edema assay, some essential oils displayed excellent anti-inflammatory properties through markedly down-regulating the relative expression of inflammatory cytokines, such as interleukin-1 beta (IL-1β) and tumor necrosis factor (TNF-α), and the essential oil of rhizomes collected from Yulin of Guangxi province showed the best anti-inflammatory effect. The antitumor activities of essential oils against microglial BV2 cell lines are also investigated, and many are quite excellent based on these IC50 values (211.07–769.06 μg/mL). Obviously, the results indicated majority of essential oils from A. officinarum rhizomes manifested extraordinary bioactivities, which makes them suitable to a large number of biomedical products, pharmaceutical preparations, natural functional nutrition and cosmetic additives.

Frankincense, Myrrh, Radix aucklandiae, Matricaria chamomilla, Jasminum sambac and Syzygium aromaticum have been widely used as Chinese herbs. The composition and anti-inflammatory activity of essential oils from Frankincense, Myrrh, R. aucklandiae, M. chamomilla, J. sambac and S. aromaticum are analyzed in this study. The dominant compositions of Frankincense essential oils are octyl acetate (39.62%), octane-1-ol (10.23%) and eucalyptol (7.42%). The major components of Myrrh essential oils are α-elemene (13.17%), β-elemene (7.92%), germacrene D (6.85%) and α-copaene (6.42%). The main compositions of R. aucklandiae essential oils are 1,4,8-cyclododecatriene (10.88%), γ-costol (10.4%), γ-gurjunenepoxide-(2) (8.18%) and caryophyllene oxide (5.67%). The major compositions of M. chamomilla oils are (E)-tonghaosu (30.83%), α-bisabolone oxide A (18.89%), α-bisabolone oxide B (10.73%) and chamazulene (6.63%). The major compounds of J. sambac and S. aromaticum essential oils are eugenol with a percentage of 52.47% and 96.71%, respectively. In TPA-induced ear edema assay, most of essential oils reveal decent anti-inflammatory activity, especially that Myrrh, R. aucklandiae and M. chamomilla essential oils are even better than commercial anti-inflammatory medicine (ibuprofen), via markedly down-regulating the expression of inflammatory cytokines, like cyclooxygenase 2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and nuclear factor-κB (NF-κB) in vivo. Therefore, it is reasonably speculated that these natural essential oils will be potential anti-inflammatory drug for inflammation with little side effects.

Because of massive applications of Zingiberaceae herbs in cosmetics, health care products and medicines, essential oils from herbs have also attracted more and more attention. In this study, chemical compositions and bioactivities of four genuine Zingiberaceae herbs essential oils from Alpinia oxyphylla Miq. (AOEOs), Kaempferia galanga L. (KGEOs), Amomum kravanh Pierre ex Gagnep.(AKEOs), and Alpinia galanga (Linn.) Willd (AGEOs) are evaluated. More than 45 components have been identified from four essential oils, and cineole (0.21–58.35 %), ethyl cinnamate (1.28–29.4 %), β-pinene (1.14–16.98 %), α-terpineol (0.16–13.89 %), α-pinene (0.03–11.42 %), p-cymene (4.11–6.93 %), and α-caryophyllene (0.04–5.46 %) are the dominants. Moreover, theses essential oils exhibit remarkable anti-inflammatory activities via markedly down-regulating the expression levels of cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1 (IL-1) in adjuvant arthritis rats. Especially, KGEOs have the most excellent anti-inflammatory activities. Furthermore, four essential oils also reveal marked cytotoxicity against LNCaP cells (IC50, 18.42–113.76 μg/mL) and B16 cells (IC50, 54.11–101.31 μg/mL), and KGEOs possess the greatest cytotoxic activity. Additionally, four essential oils display comparable antioxidant activities from its half maximal inhibitory concentration (IC50, 7.93–13.83 μg/mL) to Trolox C (IC50, 13.27 μg/mL) according to 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging ability, and KGEOs (IC50, 7.93 μg/mL) are the optimum candidate for antioxidant. Therefore, these results have indicated that the four Zingiberaceae herbs essential oils have outstanding but different bioactivities, making them ideal additives for natural functional nutrition and medicine like for antitumor, antioxidant and anti-arthritic drugs.

Objective Essential oil derived from the rhizome of Curcumin longa (CL-EO) has marked anti-inflammatory, antioxidant, antimicrobial, anticancer, and antiviral activities. However, its effect on photodamaged skin has not yet been evaluated. In this study, the anti-skin photoaging activity of CL-EO was determined by performing an ultraviolet B (UVB)-induced skin aging assay. Methods CL-EO was extracted by hydrodistillation and characterized using gas chromatography–mass spectrometry. The anti-skin aging effect was determined by topically applying 150 μl of CL-EO diluted to 1, 5, and 10% with ethanol to the dorsal area of UVB-irradiated nude mice every day except on Sunday for 8 weeks. Histological and immunohistochemical analyses were performed. Results In total, 56 compounds, which accounted for 94.36% of the contents of CL-EO, were detected. The major compounds in CL-EO were ar-turmerone (36.04%), curlone (8.78%), β-turmerone (7.05%), 8,9-dehydro-9-formyl-cycloisolongifolene (5.69%), β-sesquiphellandrene (5.39%), germacrone (4.51%), ar-curcumene (2.19%), α-himachalene (2.14%), and ledane (2.13%). Hematoxylin and eosin staining of tissue sections revealed that CL-EO decreased epidermal skin thickness. Immunohistochemistry showed that CL-EO inhibited interleukin-1β and tumor necrosis factor-α expression. Conclusions Thus, CL-EO can reduce cutaneous photoaging in a UVB-irradiated nude mouse model. Therefore, CL-EO could be used in the formulation of skin care and functional cosmetic products.

It is difficult for the current extraction and comparison target-hunting mode to be suitable for the selection of multiple targets in the offshore combat of anti-ship missiles, so the solution is hence put forward that applies the nearest-distance selector to target-hunting. Typical target-hunting situations are set to establish the target-hunting model. Explicit expression of capture probability of this nearest-distance selector is derived on the basis of reasonable simplification. The numerical simulation in typical situations demonstrates that, the performance of predetermined target-hunting is greatly improved by the distance criterion adopted in this solution, which sets the extracted multiple targets in order in terms of priority. Finally, impact extents of such factors as area of search, number of extracted objects, and target dispersion error are quantitatively evaluated. The insufficiency of using alone the method of selection of multiple nearest-distance targets is indicated with appropriate improvement actions proposed correspondingly.

Antenna polarization states always varied with scan direction, a new concept of spatial polarization characteristics of antenna is defined in this thesis. Phased-array behaves distinct property compared to mechanically-scanned antenna. The wave-guide slot phased array is used in this paper to study the polarization property with wide angle scan in airspace. Theoretical analysis and simulation proved that the lobe property and polarization changes not much in the case of small azimuth and elevation scanning angle. However, there is dramatic increase of cross polarization component in the main lobe with wide scanning angle. This characteristic can be applied to measure the target polarization scattering property in phased array radar searching stage. Based on the single polarized radar antenna, a novel polarization scattering matrix (PSM) measurement method is proposed by sufficiently utilizing the inherent polarization property of antenna which is not constant but a function of antenna's spatial scanning direction. Two orthogonal polarization channels are not required in this method. Just by using the prior knowledge of antenna polarization characteristics and improving the signal processing mode of received radar signal, the PSM of target can be obtained.

With the shrinkage of package size and the increasement of the integration, the heat dissipation in the electronics package deteriorates. Microchannel technology therefore becomes one of the most active areas of research in thermal management. This paper investigated the impact of local deformation structure in a rectangular microchannel on heat dissipation performance, and a solution was proposed by introducing thermal bimetal to the rectangular microchannel. The thermal bimetal was designed to contact with the heat source through thermal columns, and the deformation of thermal bimetal regulates the flow velocity of local cooling fluid in microchannel to achieve self-adapted heat dissipation management. The results indicated that the concave thermal bimetal rectangular microchannel outperformed than the ordinary microchannel due to its lower average temperature and lower temperature difference, therefore kept the heat source chip (e.g. PA) at a lower temperature. These efforts could be helpful for the design and optimization in microchannel cooling system for high power chip packaging.

A K-band monolithic microwave integrated circuit (MMIC) power amplifier (PA) is designed using a 0.15 um Emode GaAs pHEMT process. The MMIC PA is designed with power combining technology. Simulation results show that the MMIC PA exhibits saturation output power (Psat) of 31 dBm with power added efficiency (PAE) higher than 27.3%, and power gain higher than 21.3 dB from 24 GHz to 28 GHz, the input return loss is lower than −13dB, and the output return loss is lower than −12dB in the working band. Furthermore, the chip size is 3mm∗1.5mm including all the bonding pads.

A novel on-chip miniaturized wideband Wilkinson power divider with series LC stub is presented in this letter. This divider is analyzed and designed based on a symmetrical circuit model under even-mode and odd-mode excitation. By adding this series LC stub, good impedance matching at all the three ports and excellent isolation with additional reflection zero between two output ports are achieved. An experimental wideband power divider is implemented which achieve the bandwidth of 43.5% range from 1.8GHz to 2.8GHz with 14 dB return losses and isolation, the magnitude imbalance and phase difference of this power divider are 0.009dB and $2.17\pm 0.35^{\circ}$ , respectively. The operating frequency and bandwidth of this divider can be flexibly tuned by adjusting the value of lumped passive components. Furthermore, compact active size $(0.95\times 0.65\mathrm{mm}^{2})$ is achieved successfully.

Climate change has a crucial impact on plant resources distribution, especially on agricultural crops. Species belonging to genus Zingiber are important crop resources in China, and their rhizomes are widely used in medicine and food. In this study, the ecological distribution and richness of the genus Zingiber were analyzed using a DIVA-GIS analysis of 967 georeferenced herbarium records to produce present and future distribution simulations using the MaxEnt model. The results showed that the genus Zingiber is widely distributed in 28 provinces in China, with the greatest richness in Guangxi, Guangdong, and Yunnan. Based on our model, precipitation of the driest month, precipitation of the warmest quarter, and the minimum temperature of the coldest month were the most significant bioclimatic variables controlling the distribution of five selected Zingiber species. Future climate change will likely result in the increase of suitable habitat area for Zingiber officinale by 2.85%, but dramatically decrease that for Zingiber striolatum by 18.04%, Zingiber zerumbet by 17.87%, Zingiber corallinum by 12.40%, and Zingiber mioga by 9.46%. Thus, conservation measures should be taken to preserve these valuable resources.

The thermal (emitted) infrared frequency bands, typically from 20-40 THz and 60-100 THz, are best known for applications in thermography, such as target acquisition, surveillance, night vision, and remote sensing. This unregulated part of the spectral range offers opportunities for the development of short-range secure communications. The ‘THz Torch’ concept was recently demonstrated by the authors. This technology fundamentally exploits engineered blackbody radiation, by partitioning thermally-generated spectral noise power into pre-defined frequency channels. The energy in each channel is then independently pulse-modulated, transmitted and detected, creating a robust form of short-range secure communications in the far/mid infrared. In this paper, recent progress for the ‘THz Torch’ technology will be presented; the physical level integrity for multichannel proof-of-concept working demonstrators will be evaluated. By exploring a diverse range of methods, significant enhancements to both data rate and distance can be expected. Our thermodynamics-based approach represents a new paradigm in the sense that 19th century physics can be exploited with 20th century multiplexing concepts for low-cost 21st century ubiquitous security and defence applications in the thermal infrared range.

The ‘THz Torch’ concept was recently introduced as an ultra-low cost means of providing secure short-range wireless communications in the thermal infrared spectral range (10–100 THz). This technology exploits engineered blackbody radiation, by partitioning thermally-generated spectral noise power into pre-defined frequency channels; the energy in each channel is then independently pulsed modulated and transmitted. This technology can be further enhanced by multiplexing schemes, e.g. frequency division multiplexing (FDM) and frequency-hopping spread-spectrum (FHSS). In this paper, the end-to-end link budget analysis for a 4-channel ‘THz Torch’ working demonstrator, operating over a short transmission range of 1 cm, is given for the first time. Mathematical modelling of the end-to-end wireless link is presented. In the analysis, different bias points for the source are considered and the corresponding RMS output voltages at the receivers are calculated. The predicted results show the capability for each channel, and will serve as a guide for further improving the overall performance of this multi-channel ‘THz Torch’ system.

The thermal (emitted) infrared frequency bands, from 20–40 THz and 60–100 THz, are best known for applications in thermography. This underused and unregulated part of the spectral range offers opportunities for the development of secure communications. The ‘THz Torch' concept was recently presented by the authors. This technology fundamentally exploits engineered blackbody radiation, by partitioning thermally-generated spectral noise power into pre-defined frequency channels; the energy in each channel is then independently pulsed modulated and multiplexing schemes are introduced to create a robust form of short-range secure communications in the far/mid infrared. To date, octave bandwidth (25–50 THz) single-channel links have been demonstrated with 380 bps speeds. Multi-channel ‘THz Torch' frequency division multiplexing (FDM) and frequency-hopping spread-spectrum (FHSS) schemes have been proposed, but only a slow 40 bps FDM scheme has been demonstrated experimentally. Here, we report a much faster 1,280 bps FDM implementation. In addition, an experimental proof-of-concept FHSS scheme is demonstrated for the first time, having a 320 bps data rate. With both 4-channel multiplexing schemes, measured bit error rates (BERs) of < 10−6 are achieved over a distance of 2.5 cm. Our approach represents a new paradigm in the way niche secure communications can be established over short links.

This is our first report on the high performance 1 mm AlGaN/GaN high electron mobility transistor (HEMT) which was developed using home-made AlGaN/GaN epitaxy structures based on SiC substrate. Metal-organic chemical vapor deposition (MOCVD) was used to generate the epitaxy layers. Corresponding experiments show that the device has a gate length of 0.8 μm exhibiting drain current density of 1.16 A/mm, transconductance of 241 ms/mm, a gate-drain breakdown voltage larger than 80 V, maximum current gain frequency of 20 GHz and maximum power gain frequency of 28 GHz. In addition, the power gain under the continues wave condition is 14.2 dB with a power density of 4.1 W/mm, while under the pulsed wave condition, power gain reaches 14.4 dB with power density at 5.2 W/mm. Furthermore, the two-port network impedance characteristics display great potential in microwave application.

an optimal channel parameter model is proposed to estimate the time varying channels for OFDM systems, the proposed method adopts matrix eigenvalue decomposition of the time domain covariance function to fit channel changes. The results of channel matrix decomposition is main eigens and eigenvectors, and the model error is adjusted by the numbers of main eigen, therefore, the channel model is the statistical sense optimal ones of the finite parameters. Simulations show that good performance can be obtained in COST 207 time varying channels.

The ‘THz Torch’ concept was recently introduced by the authors for providing secure wireless communications over short distances within the thermal infrared (10-100 THz). Unlike conventional systems, thermal infrared can exploit front-end thermodynamics with engineered blackbody radiation. For the first time, a detailed power link budget analysis is given for this new form of wireless link. The mathematical modeling of a short end-to-end link is provided, which integrates thermodynamics into conventional signal and noise power analysis. As expected from the Friis formula for noise, it is found that the noise contribution from the pyroelectric detector dominates intrinsic noise. From output signal and noise voltage measurements, experimental values for signal-to-noise ratio (SNR) are obtained and compared with calculated predictions. As with conventional communications systems, it is shown for the first time that the measured SNR and measured bit error rate found with this thermodynamics-based system resembles classical empirical models. Our system analysis can serve as an invaluable tool for the development of thermal infrared systems, accurately characterizing each individual channel and, thus, enables the performance of multi-channel ‘THz Torch’ systems to be optimized.