Zhang-Cheng Hao

Multilayered substrate integrated waveguide (MSIW) elliptic filter

This letter presents the design and experiment of a novel elliptic filter based on the multilayered substrate integrated waveguide (MSIW) technique. A C-band elliptic filter with four folded MSIW cavities is simulated by using high frequency structure simulator software and fabricated with a two-layer printed circuit board process, the measured results show good performance and in agreement with the simulated results.

Development of a low cost microwave mixer using a broad-band substrate integrated waveguide (SIW) coupler

A low cost single-balanced mixer is designed using a newly designed 90/spl deg/ substrate integrated waveguide (SIW) 3-dB coupler, which takes the advantages of low cost, low profile, and high performance. An X-band single-balanced SIW mixer is designed and fabricated with a standard printed circuit board process. Measured conversion loss of 6.8dB and the wide-band response from 8.5 to 12GHz are presented.

Theory and experiment of novel frequency selective surface based on substrate integrated waveguide technology

A novel frequency selective surface (FSS) based on substrate integrated waveguide (SIW) technology is investigated with simulation and experiment. The periodic unit is made of a SIW cavity with slots on the top and bottom surfaces, and the whole FSS is fabricated on a microwave substrate with standard PCB process. The high-Q property of SIW cavities greatly improved the frequency selectivity of the FSS, which is significant for the application in antenna cover or object stealth etc. The finite difference frequency domain (FDFD) method is adopted to simulate the transmission and reflection characteristics of the proposed FSS, and the simulated results are in good agreement with the experiment data. Both simulated and experiment results show that the FSS proposed in this paper takes the advantages of low passband insertion loss, good frequency selectivity, and insensitive to the incident angle and polarization etc. Besides, the FSS can be easily fabricated using normal PCB process with low cost.

Generation of electromagnetic waves with arbitrary orbital angular momentum modes.

Recently, much attention has been focused on beams carrying orbital angular momentum (OAM) for radio communication. Here we experimentally demonstrate a planar-spiral phase plate (planar-SPP) for generating arbitrary mixed OAM beams. This proposed planar-SPP uses the concept of transmit array antenna having a perforated substrate to control the outputting phase for generating beams carrying OAM with arbitrary modes. As demonstrations, three planar-SPPs with a single OAM mode and two mixed OAM modes around 94 GHz have been investigated with design and experiments in this paper, respectively. The typical experimental intensity and phase patterns show that the proposed method of generating OAM beams really works.

A novel feeding technique for antipodal linearly tapered slot antenna array

A novel feeding system using substrate integrated waveguide (SIW) technique for antipodal linearly tapered slot array antenna (ALTSA) is presented in this paper. After making studies by simulations for a SIW fed ALTSA cell, a 1/spl times/8 ALTSA array fed by SIW feeding system at X-band is fabricated and measured, and the measured results show that this array antenna has a wide bandwidth and good performances.

A broadband substrate integrated waveguide (SIW) filter

An eleven-stage broadband SIW filter has been designed, fabricated and measured. The measured results show that the SIW filter can be operated from 9.25 GHz to 11.25 GHz with good selectivity performance. The filter has a small size, low weight, and can be integrated with other SIW components without any transitions. Its suitable for the design of microwave and millimeter wave integrated circuits

Design of a Bandwidth-Enhanced Polarization Rotating Frequency Selective Surface

An approach for the bandwidth enhancement of a polarization rotating frequency selective surface (FSS) based on the substrate integrated waveguide (SIW) technology is proposed in this communication. Compared with the previously reported polarization rotating FSS, the passband bandwidth of the proposed FSS is enhanced from 4.6% to 7.2% by introducing a triple-mode SIW cavity resonator as the periodic element. Meanwhile, better frequency response selectivity of filtering performance is achieved. The proposed FSS is made up of a periodic array of the novel triple-mode SIW cavity resonators with two orthogonal slots on the front and back surfaces for polarization rotation. The triple-mode SIW cavity resonator is achieved by placing a metallic via at the center of a dual-mode SIW cavity resonator. Bandwidth enhancement of the FSS is achieved by simultaneously exciting and properly merging together these three modes in the SIW cavity resonator. A prototype designed at Ka-band was fabricated and measured. Good agreement between the measurement and simulation results has been achieved.

A Planar Bandpass Filter Implemented With a Hybrid Structure of Substrate Integrated Waveguide and Coplanar Waveguide

In this paper, a novel planar bandpass filter is proposed, designed, and implemented with a hybrid structure of substrate integrated waveguide (SIW) and coplanar waveguide (CPW), which has the advantages of good passband and stopband performance inherited from SIW and miniaturized size accompanying with the CPW. Additional design flexibility is introduced by the hybrid structure for efficiently controlling the mixed electric and magnetic coupling, and then planar bandpass filters with controllable transmission zeros and quasi-elliptic response can be achieved. Several prototypes with single and dual SIW cavities are fabricated. The measured results verified the performance of the proposed planar bandpass filters, such as low passband insertion loss, sharp roll-off characteristics at transition band, etc.

Planar High-Gain Circularly Polarized Element Antenna for Array Applications

This paper proposes a planar high-gain circularly polarized element antenna that can be used for array applications. The substrate-integrated waveguide (SIW) cavity is designed to support dual-resonant modes, the TE120-like and TE210-like modes, for the implementation of circularly polarized radiation performance. Four rectangular radiation slots and a large perturbation, introduced by inserting a metallic via-brick into the SIW cavity, are deployed to achieve a high simulated gain of 10.28 dBi at 6.65 GHz for the proposed element. As a demonstration of an array application, a 4 × 4 array antenna is designed using the proposed element with a compact beam-forming network. Experiments are carried out to verify the designed prototypes. The measured peak gains of the designed element and array antennas are 9.6 and 20.1 dBi, respectively, which include the loss from SMA connectors. Good agreement between simulated and measured results is obtained.

Wide Stopband Bandpass Filter Implemented With Spur Stepped Impedance Resonator and Substrate Integrated Coaxial Line Technology

A novel wide stopband bandpass filter implemented with spur stepped impedance resonator (SSIR) and substrate integrated coaxial line (SICL) technology is proposed in this letter. SSIR possesses capabilities of both suppressing and staggering spurs without complicated fine-tuning, and SICL is very suitable for wide stopband applications. A prototype with compact size is fabricated, and the measured results exhibit extended stopband up to 8.76 f0 with a rejection better than 40 dB (except for a little 36.5 dB burr in 7.06 f0), or 9.36 f0 with rejection better than 30 dB.