Shunyong Hu

Ku-band 200-W Pulsed Power Amplifier Based on Waveguide Spatially Power-Combining Technique for Industrial Applications

A Ku-band 200-W pulsed solid-state power amplifier has been presented and designed by using a hybrid radial-/rectangular-waveguide spatially power-combining technique. The hybrid radial-/rectangular-waveguide power-dividing/power-combining circuit employed in this design provides not only a high power-combining efficiency over a wide bandwidth but also efficient heat sinking for the active power devices. A simple design approach of the presented power-dividing/power-combining structure has been developed. The measured small-signal gain of the pulsed power amplifier is about 51.3 dB over the operating frequency range, while the measured maximum output power at 1-dB compression is 209 W at 13.9 GHz, with an active power-combining efficiency of about 91%. Furthermore, the active power-combining efficiency is greater than 82% from 13.75 to 14.5 GHz.

Compact ultra-wideband (UWB) slotline bandpass filter with a switchable notch band

Abstract A novel switchable slotline notch-band structure is presented and applied in the ultra-wideband (UWB) bandpass filter (BPF) to switch a notch band within the passband. The PIN diodes are used for electronic switching. Based on the equivalent-circuit method, the circuit model of the presented UWB switchable notch-band BPF has been developed. The presented UWB BPF with a switchable notch band has been designed, fabricated, and measured. The fabricated UWB filter has an extremely compact size of mm. The measured results agree with the simulated ones closely. The simulated and measured results show that a notch band centered at around 5.66 GHz can be turned on or off with no obvious degradation of the performance of the UWB BPF.

Compact Dual-Passband Filter Using Spiral Resonators

A novel compact dual-band bandpass filter using spiral resonators and input/output (source-load) direct coupling structure has been presented. Two different transmission paths are utilized to realize independently controllable central frequencies and bandwidths for each passband. In addition, three transmission zeros has been introduced to improve the frequency selectivity. A dual-passband filter centered at 2.41 GHz and 4.22 GHz is designed, simulated, and fabricated to demonstrate the performance of the proposed filter structure. The measured results show good agreement with the simulated ones.

Compact Multiple-Way Power-Dividing Network with Bandpass-Filtering Response Using Spiral Resonators

ABSTRACT A new type of multiple-way out-of-phase power-dividing network with bandpass-filtering response using spiral resonators is proposed. The basic structure unit is a compact two-way out-of-phase power divider with bandpass-filtering response. The introduction of two identical spiral-type resonators can generate transmission zeros in the lower or upper stopband to implement the bandpass-filtering function. Impedance matching and out-of-phase performance are analyzed by using the even- and odd-mode method based on four-port network theory. A four-way out-of-phase power-dividing network with bandpass-filtering response is constructed and designed according to the basic two-way out-of-phase power-dividing structure. The simulated and measured results of the fabricated out-of-phase bandpass-filtering power-dividing network demonstrate the reasonable performance of impedance matching, amplitude balance, and bandpass-filtering function.

Compact dual-band filtering-response power divider with high in-band frequency selectivity

Abstract A novel compact dual-passband filtering-response power divider using modified stepped impedance resonators (SIRs) is presented. The quarter-wavelength transmission lines of conventional Wilkinson power divider are replaced by the dual-band bandpass filters to realize dual-passband bandpass response, and the phase shift of the proposed filters is tuned to be 90°. An isolation resistance R is placed at the center of the symmetric plane to realize good isolation between the two output ports. Two modified SIRs are adopted in the dual-passband filters to improve the return loss in both two passbands and control the resonant frequencies. The characteristic of the modified SIR is also analyzed. Meanwhile, the resonant frequencies can be tuned by changing impedance ratio of SIR. The source–load coupling is utilized to improve the frequency selectivity and achieve a high out-of-band rejection. A prototype of the proposed power divider is designed, fabricated, and measured. Reasonable agreement between the simulated results and measured ones is demonstrated.

Quasi-planar high-isolation four-way power divider based on capacitance compensation technology

ABSTRACT Two novel compact quasi-planar four-way high isolation power dividers are presented in this paper. The two-layer coplanar waveguide–microstrip transition structure is used to imply the isolation circuit. The equivalent circuit is given to analyze the proposed power divider. To further improve the isolation performance and output impedance matching, the capacitance compensation technology is analyzed and used to design the power divider. The measured results of the two four-way power dividers (without and with the compensating capacitance) agree with the simulated ones closely. The measured results indicate that the proposed power dividers have a low insertion loss, excellent impedance matching at all ports, good amplitude and phase balance at the output ports, and high isolation among the output ports. Moreover, the power divider with compensating capacitance demonstrates a great improvement of isolation performance and output impedance matching.

A bionic algorithm based synthesis of shaped reflector for a terahertz quasi-optical power combiner

A relative efficient procedure with a bionic algorithm is proposed, which combines a real-coded genetic algorithm and a differential operator, to synthesis a shaped reflector surface for terahertz quasi-optical power combiner. The combiner consists of a linear array of five rectangular horns, a binary phase grating as a hologram, a shaped reflector, and a receiving horn antenna. The hologram transforms the beams of the antennas into a pseudoplane wave. The transformed wave is coupled into a rectangular output horn antenna by a parabolic reflector. The final field distribution on the receiving plane can be obtained by using a bionics algorithm to optimize the mirror surface relief. The power combiner operating at 300GHz is described corresponding of 62.5% theoretical power combining efficiency.

A novel compact wideband four-way w-band waveguide power divider with low insertion loss

A novel compact wideband four-way waveguide power divider has been developed for millimeter-wave/THz array application. The power divider was realized by interconnecting three novel H-plane T-junction structures. By properly choosing the length of the interconnecting rectangular waveguide, the bandwidth of the proposed four-way power divider can be broadened. Good phase and amplitude balance of all output ports are guaranteed by its symmetrical structure. According to EM simulations, the simulated -20dB return loss bandwidth is from 74.9GHz to 98.3GHz, and good amplitude and phase balance are got in the operating band. The proposed structure has the characteristics of wideband, compact structure, and high power capacity.

Wideband out-of-phase SIW power divider with enhanced stopband

A wideband multi-way out-of-phase substrate integrated waveguide (SIW) power divider with improved rejection band by using novel hybrid multiple-via probe and multiple radial slots has been presented in this letter. The novel hybrid multiple-via probe and multiple radial slots are employed to achieve wideband and improved rejection band respectively. An eight-way out-of-phase SIW power divider is designed, fabricated, and measured. Good agreement between simulated and measured results is obtained in the desirable frequency range. The measured average insertion loss of the eight-way power divider is approximately 9.3 dB and return loss is greater than 15 dB from 3.5 GHz to 8 GHz, as well as an rejection band with more than 25 dB attenuation from 9 GHz to 11.2 GHz. A maximum amplitude imbalance of ±0.3 dB and phase imbalance of ±3° are observed over the entire operating frequency range.

Multilayer four-way power divider with improved isolation performance

Abstract A novel compact quasi-planar four-way high isolation power divider is presented in this paper. The CPW-microstrip transition structure is used to imply the isolation circuit. The equivalent circuits are given to analyse and design the proposed power divider. To improve the isolation performance and output impedance matching, the phase compensation technique is analysed and used. A four-way high isolation power divider centred at 1.9 GHz is designed and fabricated. The measured results of the four-way power divider agree with the simulated results closely. The total size of the fabricated four-way power divider is 0.18 λg × 0.21 λg. The measured results indicate that the proposed power dividers have a low insertion loss, excellent impedance matching at all ports, good amplitude and phase balance at the output ports, and high isolation among the output ports.