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Three RF switches and a phase shifter are proposed using the conductive bridging random access memory (CBRAM) technique. The fabrication process is developed with the Nafion membrane on a high-resistivity silicon substrate. The equivalent circuit model is established for each memristive RF switch. The proposed switches and the phase shifter have been validated by the good agreement achieved among the simulated, measured, and modeled results. The experimental results show that the series planar switch has the ON-state insertion loss (IL) below 1.69 dB and the OFF-state isolation over 25 dB up to 10 GHz, with the actuation voltages of 6.1~7.8/−1.5~−2 V. The parallel metal–insulator–metal (MIM) switch has the small ON-state IL below 0.45 dB and the OFF-state isolation over 18.4 dB when biased with 0.8~3.7/−0.5~−0.9 V. The series MIM switch has the ON-state IL below 0.61 dB and the OFF-state isolation over 21.9 dB with 0.7~2.3/−0.5~−0.9 V. The series MIM switch shows a good comprehensive performance of low actuation voltage, good uniformity, low IL, moderate isolation, and independent control. The phase shifter is realized with four series MIM switches, which provides a phase shift of 45° ± 5° from 3.8 to 4.3 GHz with the in-band IL of 2.25 dB. Compared with the conventional RF switchable devices, the proposed devices have the advantages of nonvolatility and low power consumption. Without depending on the electron beam lithography process and high-temperature phase change, the proposed technique is promising for reconfigurable RF circuits with mass production and feasibility to various substrates. [ABSTRACT FROM AUTHOR]

An equivalent method has been presented to analyze an $N$ -port network composed of transmission lines or coupled lines. Based on this method, a three-port coupled line with one-port short-circuited can be seemed equal to another three-port network without port coupling at the central frequency. A new Gysel out-of-phase power divider with output port spacing approaching 0 wavelength at the central frequency, arbitrary power dividing ratio, and arbitrary terminal real impedance has been proposed to reduce the size and output port spacing. A power divider with power dividing ratio $k^{2} = 3^{2}$ and a power divider with power dividing ratio $k^{2} = 1000$ have been implemented on printed circuit board (PCB). It can be observed that there is good agreement between the simulated and measured results. [ABSTRACT FROM AUTHOR]

A new power divider is proposed with a compact size. In 50- $\Omega $ systems, impedance transformation is of great importance for power dividers. Coupled microstrip lines with capacitor loaded and two short-circuited ports are introduced to properly transform impedance and increase degrees of freedom in power divider designs. Image impedance and image transfer constant of coupled microstrip lines with capacitor loaded are derived. The main structural parameters of the power divider are calculated accordingly. A special design procedure is illustrated for the proposed power divider with the capacitor loaded, which is implemented on a printed circuit board. A good agreement between the simulated model and the fabricated sample is observed, which demonstrates the validity of the proposed circuit model and the design scenario. [ABSTRACT FROM AUTHOR]

In this article, we present the analysis, design, and implementation of a wideband 10-W monolithic microwave integrated circuit power amplifier (PA), fabricated in a low-cost 0.1- $\mu \text{m}$ gallium nitride (GaN) on Si technology. The design is focused on the realization of a low-loss and wideband impedance transformation networks across 2–20 GHz using a reactive matching (RM) technique. The two-stage GaN PA achieves an average output power of 40.1 dBm and a peak output power of 41.6 dBm at 13 GHz, in the CW-mode operation, with a small-signal gain of $S_{21} > 25.5$ dB over the entire bandwidth. The average power-added efficiency (PAE) is 21%, with a peak PAE of 29% at 6 GHz. The PA chip occupies an area of $2.9\times 2.6$ mm2. To the best of our knowledge, the PA presented in this work demonstrates the highest broadband gain among the reported GaN-based RMPAs with a corresponding output power of about 10 W. [ABSTRACT FROM AUTHOR]

In this paper, a new method to develop balanced-to-unbalanced (BTU) filtering out-of-phase power divider (PD) is presented. Based on the comparison between BTU filtering out-of-phase PD and balanced-to-balanced (BTB) filter, it is found that the BTU filtering out-of-phase PD can be constructed by combining a BTB filter and an additional parallel four-port network. The design equations are derived and corresponding circuit models are given. Finally, a prototype is designed to verify the theoretical prediction. The design procedure and parameter selection are detailed. The good performance and the consistency between the simulated and measured results verify the design theory. [ABSTRACT FROM AUTHOR]

In this paper, a new single-ended-to-balanced (SETB) impedance-transforming branch-line coupler with the arbitrary power division ratio is presented. By using the matrix transformation, the standard scattering matrix and corresponding odd- and even-mode matrices are deduced from the mixed-mode scattering matrix. A simple configuration composed of four quarter-wavelength and two half-wavelength microstrip lines is proposed to achieve desired functions of the SETB branch-line coupler with the arbitrary power division ratio and arbitrary terminated impedances. The parameter selection and design principle are given. Finally, three prototypes with different power division ratios and terminated impedances are designed to verify the theoretical prediction. Impedance matching, port isolation, and mode conversion suppression are all obtained successfully for all the three fabricated SETB branch-line couplers. The proposed configuration also offers other attractive advantages including simpler configuration and design method, lower insertion loss, and good compatibility with the planar circuit technique. [ABSTRACT FROM AUTHOR]

Substrate integrated coaxial line (SICL) is a kind of planar transmission line, which can guarantee the propagation of transverse electromagnetic mode wave within a wide band. In this paper, a multichannel SICL array with coaxial lines placed in both vertical and horizontal directions is proposed for high-speed parallel data transmission. The adjacent channels of the SICL array share outer conductors for high-density integration. Moreover, the outer conductor is enhanced by metal fence to suppress the crosstalk between adjacent channels of the SICL array. In addition, a quasi-coaxial transition is designed for the proposed SICL array. A systematical design procedure is given to determine the physical dimensions of SICL array with transitions. The SICL array has flat group delay so that data can be transmitted without significant phase distortion. It is suitable for high-density integration and high-speed data transmission due to the low crosstalk and high bandwidth. To verify the advantage of the proposed SICL array, a $15 \times 3$ channel prototype is designed and fabricated in low temperature co-fired ceramic. The measured S-parameters agree well with the simulated results. The maximum bandwidth of a single channel of the SICL array is up to 56 GHz and the coupling of adjacent channels in the SICL array is less than −30 dB. Data rate of 30 Gb/s is measured for each channel with good eye diagram and low bit error rate, and hence, a total 1.35-Tb/s data rate can be achieved with the proposed $15 \times 3$ channel SICL array. [ABSTRACT FROM PUBLISHER]

A four-way microstrip power divider is designed with bandpass filtering response. The synthesized inline filter has a generalized Chebyshev response, where frequency-dependent couplings are utilized. All of the critical parameters, including the characteristic impedances and electrical lengths, can be determined by our derived closed-form formulas. By extending the inline filter, the configuration of four-way power divider is obtained. Then, three isolation resistors are properly selected according to the even-/odd-mode analysis. The proposed four-way filtering power divider has low in-band insertion loss and high frequency selectivity. It can provide the in-band return loss and isolation between outputs better than 16.7 and 17.5 dB, respectively . [ABSTRACT FROM PUBLISHER]

This paper presents novel bandpass filters by using a triple-mode dielectric resonator (DR) implemented in a substrate integrated waveguide (SIW). The resonant frequency and unloaded Q-factor of the DR were first calculated and simulated by Ansoft HFSS. The dimensions of the DR were then determined. A single triple-mode SIW loaded with a DR filter with tuning elements was designed, simulated, and measured. Spurious suppression with source and load couplings, as well as fabrication tolerance, was analyzed. A six-mode filter that uses two DRs was also proposed and measured. These filters exhibit close agreements between the simulation and measurement results and have the advantages of low insertion loss, compact configuration, and easy integration with other planar circuits. The proposed concept is very attractive for designing low cost, low insertion loss, and miniaturized filters for wireless communication systems. [ABSTRACT FROM PUBLISHER]

A planar microstrip crossover is proposed by using a stub-loaded ring structure with lumped inductors to realize good transmission and isolation performances for three intersecting channels. It can take the place of three conventional dual-channel crossovers. Since the component is with a sixfold rotational symmetric configuration, it can be analyzed by using its eigen-admittances and the even-/odd-mode theory. The analytical equations are derived to generate the design curves to determine the circuit parameters, operating bandwidth and transmission phase. The influence of the utilized lumped inductors on the crossover performance is also considered. A prototype is developed at 1.0 GHz with an occupied area of 0.308\,\times\,0.294 \lambdag^{2}, where \lambdag is the guided wavelength of the central frequency. The performances of diagonal transmission, port matching, and isolation between different channels are achieved with a 6% operating bandwidth, which has been demonstrated by the theoretical, simulated, and measured results. [ABSTRACT FROM AUTHOR]

In this paper, the balanced-to-balanced Gysel power divider is proposed with bandpass filtering response for the first time. The component is based on a ring structure and designed with an extended coupled-resonator circuit model. The characteristic impedances, electrical lengths, and isolation resistance are calculated analytically by our derived equations, according to the design specifications of the filtering power divider. The achievable bandwidth is from about 3% to 12%. As an example, a fabricated prototype occupies an area of 0.97\,\times\,0.87 \lambdag^{2}, whose bandwidth is 8.4%. It has low differential-mode in-band insertion loss, good magnitude, and phase balances between two output ports, good isolation, and good suppression of common-mode noises and mode conventions. Based on stub-loaded sections, another prototype is realized for miniaturization, whose occupied area is reduced to 0.67\,\times\,0.63 \lambdag^{2}. In comparison with the original prototype, the central insertion loss is increased by 0.13 dB, and the rejection band of common-mode and mode-conversion noises is narrowed by 21%. [ABSTRACT FROM AUTHOR]

In this paper, a balanced-to-balanced power divider is proposed, for the first time, with arbitrary power division, which can be regarded as the balanced form of a Gysel power divider. The constraint rules are provided for its mixed-mode and single-ended S-parameters. The six-port network is analyzed by simplifying it to two-port networks with other ports matched at the central frequency. Its critical characteristic impedances are then calculated analytically by our derived equations according to the desired differential-mode power division ratio. The maximum achievable power division ratio is \1:4.69^2 when the characteristic impedances are limited within the realizable range of 20–120 \Omega. The impacts of several freely selected design parameters on the operating bandwidth are explored numerically. A prototype is realized by microstrip lines and lumped resistors with the power division ratio of \1:3^2. The balanced-to-balanced performances of unequal power division, low differential-mode insertion loss, good suppression of common-mode noises, and mode conventions have been demonstrated by the simulated and measured results of the balanced-to-balanced power divider prototype. [ABSTRACT FROM PUBLISHER]

A new dual-bandpass 180^\circ hybrid coupler, based on four properly designed shorted-stub loaded stepped-impedance resonators, is proposed in this paper. In order to construct the collaboratively designed coupler/filter, the resonators are coupled magnetically and electrically with each other through three shorted stubs and an open coupled line, respectively. According to the approach of filter synthesis and the derived design equations, the characteristic admittances and electrical lengths of the resonators and coupling sections are determined to achieve the desired resonant frequencies, external Q factors, and internal coupling coefficients for dual passbands. A design procedure is provided. The design flexibilities for ratios of central frequencies and achievable bandwidths are explored. The component shows both filtering and power dividing functions within two specific passbands, whose good performances are demonstrated by the simulated and measured results. The two second-order passbands of a fabricated prototype are located at 2.42 and 5.84 GHz, with 4.6% and 5.2% bandwidths, respectively. The insertion losses are 1.0 and 1.4 dB over 3-dB power division. The isolations are better than 23.5 and 32.8 dB. In both the in-phase and out-of-phase responses, the in-band amplitude and phase imbalances are always within -1.6–0.6 dB and -\6.5^\circ–9.5^\circ, respectively. [ABSTRACT FROM AUTHOR]

In this paper, a new balanced-to-balanced power divider/combiner is proposed. By using matrix transformation, two three-port networks for the odd- and even-mode circuit models are deduced, based on the constraint rules of the mixed-mode S-parameters. In order to satisfy the two required scattering matrices simultaneously, the resistances of lumped elements, the characteristic impedances and electrical length of transmission lines are selected appropriately. Then, a planar microstrip structure is designed to realize the proposed balanced-to-balanced power divider/combiner with equal power division. The theoretical, simulated and measured results all show a good mixed-mode performance. In the measurement, the maximum differential-mode transmission coefficient is -\ 3.2 dB, the best differential-mode isolation is 47.2 dB, and the fractional bandwidth of its operating band is approximately 20.8%. [ABSTRACT FROM PUBLISHER]

A cross-coupled substrate-integrated evanescent-mode waveguide filter is proposed with a quasi-elliptic frequency response. It is realized with a coplanar waveguide as a nonresonating node to provide an equivalent negative coupling coefficient. The filter prototype is developed with folded and ridge substrate-integrated waveguides (SIWs) in low-temperature co-fired ceramic. Since evanescent-mode and cross-coupling techniques are used in the design of filters, about 90% area reduction and more than 60% volume reduction are achieved, in comparison with conventional planar cavity-coupled SIW filters. Their unloaded Q factor is also improved. In particular, the spurious suppression characteristic of the direct-coupled evanescent-mode waveguide filter is kept by the cross-coupled filter with the nonresonating node structure. All these merits are demonstrated numerically, as well as experimentally, with good agreement obtained between the measured and simulated S-parameters. [ABSTRACT FROM PUBLISHER]

A new type of half-mode substrate integrated waveguide (SIW) periodically loaded with different lumped elements and structures is proposed in this paper. The propagation constants, Bloch impedances, and voltage distributions of the Floquet TE-modes are all characterized by solving the eigenvalues of the generalized transmission matrix of a single period. Several typical capacitor-loaded, inductor-loaded, corrugated, and electromagnetic- bandgap (EBG)-loaded half-mode SIWs were fabricated to demonstrate their modal dispersion behavior. The measured and simulated S-parameters, group delays, and simulated electric field distributions in these novel structures are presented, with good agreements obtained for all samples. In particular, their unique controllable cutoff frequencies, multiple bandgaps, and separated monomode regions are also illuminated numerically and experimentally. To further show their applications, a tunable phase shifter is developed using a varactor-loaded structure, with its 3-dB bandwidth of 50% and a maximal tunable range of 88° . In addition, a bandpass filter based on EBG-loaded half-mode SIW is also realized and presented with its special characteristics. It demonstrates that the filter has a sharp upper slope side and a good performance of spurious suppression. [ABSTRACT FROM AUTHOR]

An empirical large-signal III-V field-effect transistor (FET) model has been developed. Three improved drain-source current (I-V) modeling equations capable of representing arbitrarily shaped transconductance (Gm) curves are proposed from level-i to level-3. These models are characterized by the static dc and the multibias pulsed I-V measurements along with their dependences on temperature, so as to account for the frequency dispersion and the self-heating effects. By partitioning the Gm plots into five regions, specific parameters of the various model levels can be directly associated with the regions. Besides, the fitting parameters have inherent consistent definitions among different model levels, where some of the key model parameters canbe extracted directly from measurements. For the gate-charge formulation (Q-V), a novel charge-conservative gate charge model is presented to accurately trace the nonlinear gate-source (Cgs) and gate-drain (Cgd) capacitance values. The comprehensive large-signal model is then validated by comparing the predicted I-V, C-V, S-parameters as well as power characteristics with the measured results of III-V FETs. [ABSTRACT FROM AUTHOR]

The authors of the original above-named article [ibid., vol. 60, no. 9, pp. 2791?2798, Sep. 2012] appreciate the comments by M.-J. Park [ibid., vol. 61, 2013]. The authors agree that their proposed balanced-to-balanced power divider/combiner structure can be simplified into the form proposed in the comments of Park when only the circuit performance at the central frequency is considered. The main reason is that the half-wavelength transmission line can be regarded as an ideal phase inverter with special properties, including those described by Park [see (1)?(4)]. However, the two structures have different characteristics at other frequencies, and it should also be pointed out that the curves in Park's Fig. 3 cannot completely describe the frequency responses of the structure since it is not symmetric to its middle plane any more. From a theoretical analysis and simulations presented, it can be concluded that the balanced-to-balanced power dividers originally presented by Park and the authors and this letter are equivalent to each other at the central frequency due to the special properties of ideal phase inverters, and all of them can be converted from a two-way single-ended Wilkinson power divider. The authors' proposed power divider had four resistors and a symmetric configuration, which provides two differential-mode outputs with the same magnitude and the best bandwidth. The power dividers proposed by Park and this letter have fewer resistors, but their two outputs are not symmetric and the operating bands are also narrowed. Therefore, if symmetric performances and relatively large bandwidth are prior in design, the originally proposed four-resistor structure is preferred. When compact size and few resistors are desired, the type C one-resistor structure, given in Fig. 1(d) of this reply, is more suitable. [ABSTRACT FROM AUTHOR]