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In this paper a very compact design of a dual-band band pass filter (D-BPF) using dual composite right-/left-handed (D-CRLH) and open-loop ring (OLR) resonators is presented. To overcome the frequency ratio limitations of D-CLRH resonators technique, the D-BPF design combines D-CRLH and OLR resonators to finally perform a D-BPF. The filter covers the 2.6 and 3.5 GHz spectrums for 4G and 5G applications, respectively. The reported D-BPF is designed and optimized using ADS software, and is implemented on a Rogers RO5880 substrate with a relative dielectric constant of 2.2 and thickness of 0.787 mm. The overall compact size is 8×8×0.787 mm^3. To our knowledge, this design is considered as the most compact and smallest size dual-bandpass filters.

This article presents a novel design method for inline bandpass filters exhibiting prescribed transmission zeros (TZs) above the passband. The basic structure consists of evanescent mode rectangular waveguide (RW) sections loaded with split ring resonators (SRRs) that are arranged on the cross section. For the first time, the position of the TZs is controlled above the bandwidth by turning the SRR. The proposed design method uses a cascaded triplet topology to simplify the control over the crosscouplings. A prototype is fabricated and measured in the X-band to validate the practical viability of the presented filters, revealing good agreement with simulated results and high-performance characteristics for a moderate bandwidth: insertion loss IL= 0.85 dB, return loss RL = 19 dB, and fractional bandwidth FBW = 5.69%. In addition to achieving control over the position of the prescribed TZs in the filter frequency response compared to other SRR-based filters reported in the literature, significant size reduction has also been obtained with respect to other triplet implementations. This design method is extended by adding TZs below the bandwidth. To do this, the sign of one of the main couplings in the triplet is reversed by arranging the SRR along the E-plane of the evanescent RW. A fifth-order bandpass filter with TZs at both sides of the passband is designed to demonstrate the effectiveness of the proposed method.

Biomedical implantable antennas play a vital role in medical telemetry applications. These types of biomedical implantable devices are very helpful in improving and monitoring patients' living situations on a daily basis. In the present paper, a miniaturized footprint, thin-profile bear-shaped in-body antenna operational at 915 MHz in the industrial, scientific, and medical (ISM) band is proposed. The design is a straightforward bear-shaped truncated patch excited by a 50-Omega coaxial probe. The radiator is made up of two circular slots and one rectangular slot at the feet of the patch, and the ground plane is sotted to achieve a broadsided directional radiation pattern, imprinted on a Duroid RT5880 roger substrate with a typical 0.254-mm thickness (epsilon(r) = 2.2, tan delta = 0.0009). The stated antenna has a complete size of 7 mm x 7 mm x 0.254 mm and, in terms of guided wavelength, of 0.027 lambda(g) x 0.027 lambda(g) x 0.0011 lambda(g). When operating inside skin tissues, the antenna covers a measured bandwidth from 0.86 GHz to 1.08 GHz (220 MHz). The simulations and experimental outcomes of the stated design are in proper contract. The obtained results show that the calculated specific absorption rate (SAR) values inside skin of over 1 g of mass tissue is 8.22 W/kg. The stated SAR values are lower than the limitations of the federal communications commission (FCC). Thus, the proposed miniaturized antenna is an ultimate applicant for in-body communications., QC 20220420

In this work, a novel millimeter-wave circularly polarized patch antenna is presented. The antenna offers wide bandwidth, high gain, compact size, simple geometry, low profile and wide axial ratio. The proposed antenna is designed on the top side of Rogers RT/duroid 6002 with thickness of 0.79mm. The analysis and numerical simulation of the proposed antenna is performed using the full-wave electromagnetic simulator, HFSS., QC 20230607

A leaky-wave antenna (LWA) based on the double-layer substrate integrated waveguide (SIW) that has a wide scanning range within a narrow bandwidth is proposed. The LWA consists of two layers, each of which consists of multiple elemental SIWs arranged in parallel at each layer while the direction of the SIWs in the two layers are at an oblique angle to each other. The elemental top layer SIWs are connected to those in the bottom layer though parallelogram-shaped slots, so that the two layers together form a double-layer SIW. Thin slots etched on the upper surface of each elemental SIW of the top layer act as radiating structures. As the phase difference between the radiating slots of adjacent elemental SIWs can be enlarged by the waveguide length, wide-angle beam scanning is achieved within a specific frequency bandwidth. The proposed LWA has a scanning range from -58 degrees to 49 degrees in a relative bandwidth of 6.45%, from 12.75 GHz to 13.6 GHz. The scanning rate (SR), defined as the scanning range divided by the relative bandwidth, is up to 16.5. The size of structure is compact, which is 4.0 lambda(0) x 3.6 lambda(0) x 0.04 lambda(0). The proposed LWA is suitable for radar or communication system applications., QC 20210303

A compact ultra-wideband (UWB) and triband patch antenna with the partial ground plane is presented in this paper. Initially, the antenna is designed for UWB applications, operating at the UWB portion of the spectrum ranging from 3.1 GHz to 10.6 GHz, then it is modified to operate at three distinct frequencies of 2.45 GHz, 5 GHz, and 10.2 GHz. The proposed antenna is inspired by a classic rectangular patch antenna in which slots, stubs, and defected ground structure (DGS) were introduced to increase its operational bandwidth. Good results in terms of return loss are found in all resonant frequencies as well as for the single wideband. In addition, the proposed antenna has been compared with related works in the literature, to highlight its potential for future UWB and multiband portable devices.

A compact ultra-wideband (UWB) and triband patch antenna with the partial ground plane is presented in this paper. Initially, the antenna is designed for UWB applications, operating at the UWB portion of the spectrum ranging from 3.1 GHz to 10.6 GHz, then it is modified to operate at three distinct frequencies of 2.45 GHz, 5 GHz, and 10.2 GHz. The proposed antenna is inspired by a classic rectangular patch antenna in which slots, stubs, and defected ground structure (DGS) were introduced to increase its operational bandwidth. Good results in terms of return loss are found in all resonant frequencies as well as for the single wideband. In addition, the proposed antenna has been compared with related works in the literature, to highlight its potential for future UWB and multiband portable devices.

A compact ultra-wideband (UWB) and triband patch antenna with the partial ground plane is presented in this paper. Initially, the antenna is designed for UWB applications, operating at the UWB portion of the spectrum ranging from 3.1 GHz to 10.6 GHz, then it is modified to operate at three distinct frequencies of 2.45 GHz, 5 GHz, and 10.2 GHz. The proposed antenna is inspired by a classic rectangular patch antenna in which slots, stubs, and defected ground structure (DGS) were introduced to increase its operational bandwidth. Good results in terms of return loss are found in all resonant frequencies as well as for the single wideband. In addition, the proposed antenna has been compared with related works in the literature, to highlight its potential for future UWB and multiband portable devices.

This letter presents a high-selectivity compact microstrip bandpass filter (BPF) with a flexibly controllable bandwidth, based on multi-path source-load couplings and a square-type split-ring resonator (STSRR). An STSRR, which is enclosed between the capacitively coupled source and load transmission feed lines, forms the structure of the proposed BPF. The main advantages of the proposed BPF lie in its simple structure and high selectivity due to multiple transmission zeros generated by multipath source-load couplings based on STSRR-enabled magnetic coupling between the feed lines with dual capacitive couplings. In addition, the bandwidth of the proposed BPF can be flexibly controlled by varying the magnetic coupling gap between the STSRR and the feed lines. The measured pass-band insertion and return loss of 0.83 and 27.23 dB, respectively, for a prototype BPF with a central frequency of 3.83 GHz and corresponding bandwidth of 12.98%, demonstrates the validity of the proposed method.

In this paper, a Wilkinson power divider is modified using four-series delta-stub and folded stepped-impedance transmission line (FSITL) in order to achieve a reduced circuit size of 84% and fractional bandwidth of 116%. Series delta-stubs are used instead of open shunt stubs to obtain an optimum shifting frequency and wider bandwidth. Folded stepped-impedance transmission line (FSITL) is used to achieve reduced circuit size. The proposed power divider is fabricated using RT/duroid 5880 substrate with thickness of 0.38 mm. The dimension of the power divider is 13 mm × 6.5 mm. The proposed power divider has typical power division of -3 dB and insertion loss less than -1 dB, better than -13 dB of isolation, less than -10 dB return loss and phase imbalances less than 2° from 1.5 to 3 GHz. Both simulation and measurement results show a good agreement.

In this paper, a Wilkinson power divider is modified using four-series delta-stub and folded stepped-impedance transmission line (FSITL) in order to achieve a reduced circuit size of 84% and fractional bandwidth of 116%. Series delta-stubs are used instead of open shunt stubs to obtain an optimum shifting frequency and wider bandwidth. Folded stepped-impedance transmission line (FSITL) is used to achieve reduced circuit size. The proposed power divider is fabricated using RT/duroid 5880 substrate with thickness of 0.38 mm. The dimension of the power divider is 13 mm × 6.5 mm. The proposed power divider has typical power division of -3 dB and insertion loss less than -1 dB, better than -13 dB of isolation, less than -10 dB return loss and phase imbalances less than 2° from 1.5 to 3 GHz. Both simulation and measurement results show a good agreement.

This letter presents a high-selectivity compact microstrip bandpass filter (BPF) with a flexibly controllable bandwidth, based on multi-path source-load couplings and a square-type split-ring resonator (STSRR). An STSRR, which is enclosed between the capacitively coupled source and load transmission feed lines, forms the structure of the proposed BPF. The main advantages of the proposed BPF lie in its simple structure and high selectivity due to multiple transmission zeros generated by multipath source-load couplings based on STSRR-enabled magnetic coupling between the feed lines with dual capacitive couplings. In addition, the bandwidth of the proposed BPF can be flexibly controlled by varying the magnetic coupling gap between the STSRR and the feed lines. The measured pass-band insertion and return loss of 0.83 and 27.23 dB, respectively, for a prototype BPF with a central frequency of 3.83 GHz and corresponding bandwidth of 12.98%, demonstrates the validity of the proposed method.

In this paper, a Wilkinson power divider is modified using four-series delta-stub and folded stepped-impedance transmission line (FSITL) in order to achieve a reduced circuit size of 84% and fractional bandwidth of 116%. Series delta-stubs are used instead of open shunt stubs to obtain an optimum shifting frequency and wider bandwidth. Folded stepped-impedance transmission line (FSITL) is used to achieve reduced circuit size. The proposed power divider is fabricated using RT/duroid 5880 substrate with thickness of 0.38 mm. The dimension of the power divider is 13 mm × 6.5 mm. The proposed power divider has typical power division of -3 dB and insertion loss less than -1 dB, better than -13 dB of isolation, less than -10 dB return loss and phase imbalances less than 2° from 1.5 to 3 GHz. Both simulation and measurement results show a good agreement.

In this paper, a Wilkinson power divider is modified using four-series delta-stub and folded stepped-impedance transmission line (FSITL) in order to achieve a reduced circuit size of 84% and fractional bandwidth of 116%. Series delta-stubs are used instead of open shunt stubs to obtain an optimum shifting frequency and wider bandwidth. Folded stepped-impedance transmission line (FSITL) is used to achieve reduced circuit size. The proposed power divider is fabricated using RT/duroid 5880 substrate with thickness of 0.38 mm. The dimension of the power divider is 13 mm × 6.5 mm. The proposed power divider has typical power division of -3 dB and insertion loss less than -1 dB, better than -13 dB of isolation, less than -10 dB return loss and phase imbalances less than 2° from 1.5 to 3 GHz. Both simulation and measurement results show a good agreement.

This letter presents a high-selectivity compact microstrip bandpass filter (BPF) with a flexibly controllable bandwidth, based on multi-path source-load couplings and a square-type split-ring resonator (STSRR). An STSRR, which is enclosed between the capacitively coupled source and load transmission feed lines, forms the structure of the proposed BPF. The main advantages of the proposed BPF lie in its simple structure and high selectivity due to multiple transmission zeros generated by multipath source-load couplings based on STSRR-enabled magnetic coupling between the feed lines with dual capacitive couplings. In addition, the bandwidth of the proposed BPF can be flexibly controlled by varying the magnetic coupling gap between the STSRR and the feed lines. The measured pass-band insertion and return loss of 0.83 and 27.23 dB, respectively, for a prototype BPF with a central frequency of 3.83 GHz and corresponding bandwidth of 12.98%, demonstrates the validity of the proposed method.

A printed two-dipole array antenna with a high front-back ratio is proposed for ultra-high-frequency (UHF) radio-frequency identification handheld readers. The proposed antenna is a parasitic dual-element array with the ends of both elements folded back towards each other for additional coupling. The antenna features a compact size of 89 mm x 87 mm and works properly with satisfactory gain and total efficiency in the wide UHF band of 860-960 MHz. Furthermore, the front-to-back ratio of 15-26.8 dB, the peak gain of 3.7-4.4 dBi and the total efficiency of more than 80% in the Federal Communication Commission (FCC) band make the proposed antenna attain high performance in the FCC band., QC 20151006

Wavelength beam combining of diode lasers produces the intensity and brightness necessary for metal cutting and welding that previously required more powerful and more expensive laser systems. The wavelength beam-combining fiber-coupled diode laser is the first direct-diode laser that is bright enough to cut and weld metal. Although diode lasers are the highest efficiency lasers, until recently their brightness has been relatively low compared to that of other kW-class lasers used in industrial applications. Lincoln Laboratory's fundamental breakthrough in wavelength beam-combining (WBC) has enabled the development of a system that has the laser brightness necessary for industrial use., Published in Tech Notes, 2012. This technology won a 2012 R&D 100 Award.

In this paper, a filter based on Composite Right/Left Handed (CRLH) structures is presented, wide pass band is obtained due to the balanced CRLH properties. Besides, it has Complementary Split-Ring Resonator (CSRR) units etched on ground plane, which improves signal rejection in its upper stop band. The CSRRs work as a stop band filter in a band near the main pass band of the filter and bring in equivalent negative permittivity. CSRRs and CRLH units occupy the two sides of substrate respectively and have little mutual affection in the pass band, so either structure can be designed independently, without considering the effect from the other. The improvement occupy no additional space, the size is as large as the original filter. Detailed design procedure is illustrated. Good agreements among simulation and measurement results are achieved. In addition, the filter has a semi-enclosed structure and compact size, and the performance is greatly improved., QC 20120904

A novel compact bandstop filter composed of three cascaded uniplanar double spiral resonant cells (UDSRCs) for high attenuation rates is presented. Through the equivalent circuit prediction and parametric analysis, it is found that the UDSRC exhibits two controllable transmission zeros with great design flexibility through tuning the geometry parameters in a small range. Then, the influence of the stage separation between each UDSRC is investigated in order to get the appropriate stage separation. After optimization, a demonstration bandstop filter has been fabricated and measured. The results show that the attenuation rates on the lower and upper sides are 95dB/GHz and 155dB/GHz, respectively. Without any shunt stubs introduced, the length and width of the three cells are 28% and 4% of the guided wavelength at the mid-stopband frequency.

A compact printed multimode antenna for Multiple-Input Multiple-Output (MIMO) systems is presented. The antenna consists of a slotted metallic ring antenna excited by four L-shaped microstrip feeding lines, which are necessary to generate four orthogonal radiating modes. The proposed antenna exhibits a performance similar to traditional antenna arrays in MIMO systems, and due to its compact size it is very suitable for mobile terminals or sensors. The Theory of Characteristic Modes is first used to identify the different radiating modes of the antenna and then a set of feeding configurations is proposed so as to excite these modes. A compact printed 2-stage network of 180° hybrid couplers is implemented to feed the proposed antenna. Measured S-parameters and radiation patterns confirm the excellent behavior of the proposed antenna.

A compact printed multimode antenna for Multiple-Input Multiple-Output (MIMO) systems is presented. The antenna consists of a slotted metallic ring antenna excited by four L-shaped microstrip feeding lines, which are necessary to generate four orthogonal radiating modes. The proposed antenna exhibits a performance similar to traditional antenna arrays in MIMO systems, and due to its compact size it is very suitable for mobile terminals or sensors. The Theory of Characteristic Modes is first used to identify the different radiating modes of the antenna and then a set of feeding configurations is proposed so as to excite these modes. A compact printed 2-stage network of 180° hybrid couplers is implemented to feed the proposed antenna. Measured S-parameters and radiation patterns confirm the excellent behavior of the proposed antenna.

A novel compact bandstop filter composed of three cascaded uniplanar double spiral resonant cells (UDSRCs) for high attenuation rates is presented. Through the equivalent circuit prediction and parametric analysis, it is found that the UDSRC exhibits two controllable transmission zeros with great design flexibility through tuning the geometry parameters in a small range. Then, the influence of the stage separation between each UDSRC is investigated in order to get the appropriate stage separation. After optimization, a demonstration bandstop filter has been fabricated and measured. The results show that the attenuation rates on the lower and upper sides are 95dB/GHz and 155dB/GHz, respectively. Without any shunt stubs introduced, the length and width of the three cells are 28% and 4% of the guided wavelength at the mid-stopband frequency.

A novel compact bandstop filter composed of three cascaded uniplanar double spiral resonant cells (UDSRCs) for high attenuation rates is presented. Through the equivalent circuit prediction and parametric analysis, it is found that the UDSRC exhibits two controllable transmission zeros with great design flexibility through tuning the geometry parameters in a small range. Then, the influence of the stage separation between each UDSRC is investigated in order to get the appropriate stage separation. After optimization, a demonstration bandstop filter has been fabricated and measured. The results show that the attenuation rates on the lower and upper sides are 95dB/GHz and 155dB/GHz, respectively. Without any shunt stubs introduced, the length and width of the three cells are 28% and 4% of the guided wavelength at the mid-stopband frequency.

A novel compact bandstop filter composed of three cascaded uniplanar double spiral resonant cells (UDSRCs) for high attenuation rates is presented. Through the equivalent circuit prediction and parametric analysis, it is found that the UDSRC exhibits two controllable transmission zeros with great design flexibility through tuning the geometry parameters in a small range. Then, the influence of the stage separation between each UDSRC is investigated in order to get the appropriate stage separation. After optimization, a demonstration bandstop filter has been fabricated and measured. The results show that the attenuation rates on the lower and upper sides are 95dB/GHz and 155dB/GHz, respectively. Without any shunt stubs introduced, the length and width of the three cells are 28% and 4% of the guided wavelength at the mid-stopband frequency.

A novel compact bandstop filter composed of three cascaded uniplanar double spiral resonant cells (UDSRCs) for high attenuation rates is presented. Through the equivalent circuit prediction and parametric analysis, it is found that the UDSRC exhibits two controllable transmission zeros with great design flexibility through tuning the geometry parameters in a small range. Then, the influence of the stage separation between each UDSRC is investigated in order to get the appropriate stage separation. After optimization, a demonstration bandstop filter has been fabricated and measured. The results show that the attenuation rates on the lower and upper sides are 95dB/GHz and 155dB/GHz, respectively. Without any shunt stubs introduced, the length and width of the three cells are 28% and 4% of the guided wavelength at the mid-stopband frequency.

A novel compact bandstop filter composed of three cascaded uniplanar double spiral resonant cells (UDSRCs) for high attenuation rates is presented. Through the equivalent circuit prediction and parametric analysis, it is found that the UDSRC exhibits two controllable transmission zeros with great design flexibility through tuning the geometry parameters in a small range. Then, the influence of the stage separation between each UDSRC is investigated in order to get the appropriate stage separation. After optimization, a demonstration bandstop filter has been fabricated and measured. The results show that the attenuation rates on the lower and upper sides are 95dB/GHz and 155dB/GHz, respectively. Without any shunt stubs introduced, the length and width of the three cells are 28% and 4% of the guided wavelength at the mid-stopband frequency.

This paper describes a novel Flexo, Screen and Inkjet printed rounded edges bowtie antenna with T-matching stubs on paper, Kapton (HN) and Teonex Q51 substrate. Paper is one of the paramount nominees for Radio Frequency Identification (RFID) tags, for the reason that it is one of the widely and the cheapest available substrates. Kapton (HN) and Teonex Q51 are distinguished for their flexibility and reliability. The antenna exhibits compact size with outstanding read range of 4 meters and complete coverage of UHF RFID band (860-960 MHz). The results show extreme immunity of versatile antenna against harsh environments. These antennas are flexible which give autonomy for their applications., QC 20110418