Soumava Mukherjee

Broadband Substrate Integrated Waveguide Cavity-Backed Bow-Tie Slot Antenna

A novel design technique for broadband substrate integrated waveguide cavity-backed slot antenna is demonstrated in this letter. Instead of using a conventional narrow rectangular slot, a bow-tie-shaped slot is implemented to get broader bandwidth performance. The modification of the slot shape helps to induce strong loading effect in the cavity and generates two closely spaced hybrid modes that help to get a broadband response. The slot antenna incorporates thin cavity backing (height <;0.03λ0 ) in a single substrate and thus retains low-profile planar configuration while showing unidirectional radiation characteristics with moderate gain. A fabricated prototype is also presented that shows a bandwidth of 1.03 GHz (9.4%), a gain of 3.7 dBi over the bandwidth, 15 dB front-to-back ratio, and cross-polarization level below -18 dB.

Substrate Integrated Waveguide Cavity-Backed Dumbbell-Shaped Slot Antenna for Dual-Frequency Applications

In this letter, a novel dumbbell-shaped slot along with thin substrate integrated waveguide (SIW) cavity backing ( ) is used to design dual-frequency slot antenna. The proposed design exhibits unidirectional radiation characteristics, high gain, high front to back ratio (FTBR) at each resonant frequency while maintaining low profile, planar configuration. The unique slot shape helps to introduce complex current distribution at different frequencies that results in simultaneous excitation of hybrid mode at higher frequency along with conventional TE120 mode in the cavity. Both conventional mode and the hybrid mode helps the modified slot to radiate at the corresponding resonant frequencies resulting in compact, dual-frequency antenna. A fabricated prototype is also presented which resonates at 9.5 GHz and 13.85 GHz with impedance bandwidth more than 1.5% at both resonant frequencies and gain of 4.8 dBi and 3.74 dBi respectively. The front-to-back ratio of the antenna are above 10 dB at both operating frequencies.

Design of broadband power divider based on Substrate-Integrated Waveguide technology

In this paper, design principles for implementation of broadband T-type and Y-type power divider based on Substrate-Integrated Waveguide (SIW) technology has been presented. Different design curves have been developed based on simulation results and are used to implement 1×2 power dividers of Y-type and T-type. Finally, by cascading T-type and Y-type stages a 1×4 Power divider of equal division is designed and simulated. The proposed design shows a broad bandwidth (-20 dB) of 18.3% and insertion-loss Bandwidth (1%) of 17.86%.

Design of Self-Diplexing Substrate Integrated Waveguide Cavity-Backed Slot Antenna

In this letter, a novel design technique to realize planar self-diplexing slot antenna using substrate integrated waveguide (SIW) technology is presented. The proposed antenna uses a bowtie-shaped slot backed by SIW cavity, which is excited by two separate feedlines to resonate at two different frequencies in X-band (8-12 GHz). By properly optimizing the antenna dimensions, a high isolation of better than 25 dB between two input ports is achieved, which helps to introduce self-diplexing phenomenon in the proposed design. The behavior of the individual cavity modes at two resonant frequencies is explained using half-mode theory. The proposed antenna resonates at 9 and 11.2 GHz with unidirectional radiation pattern and a high gain of 4.3 and 4.2 dBi, respectively.

Design of a broadband coaxial to substrate integrated waveguide (SIW) transition

In this paper, a novel design of broadband coaxial to substrate integrated waveguide (SIW) transition has been implemented. The difficulties to get impedance matching between SIW and excitation port especially for thin substrate has been investigated and design steps to overcome the problem has been discussed. A two port SIW section using back-to-back configuration of the proposed transition is designed to operate at X-band (8-12 GHz) and fabricated. The measured result shows a broad bandwidth (30%) and an insertion loss of 1.2 dB in the operating band.

Bandwidth enhancement of substrate integrated waveguide cavity backed slot antenna by offset feeding technique

In this paper, a novel technique to enhance the bandwidth of substrate integrated waveguide cavity backed slot antenna is demonstrated. The feeding technique to the cavity backed antenna has been modified by introducing offset feeding of microstrip line along with microstrip to grounded coplanar waveguide transition which helps to excite TE120 mode in the cavity and also to get improvement in impedance matching to the slot antenna simultaneously. The proposed antenna is designed to resonate in X band (8-12 GHz) and shows a resonance at 10.2 GHz with a bandwidth of 4.2% and a gain of 5.6 dBi, 15.6 dB front to back ratio and -30 dB maximum cross polarization level.

Periodic leaky-wave array antenna on substrate integrated waveguide for gain enhancement

In this paper, 2-elements and 4-elements substrate integrated waveguide (SIW) based leaky-wave array antennas are presented and their performances are compared. The enhanced gain and scan angles for 2-elements are 15.4 dBi and 45° respectively and for 4-elements the same is 18.4 dBi and 30° respectively. In the final design of 4-elements array antenna, sinusoidal variation of slot length is used to reduce the side lobe level (SLL). A 1×4 cascaded SIW power divider with effective matching port is used to feed the antenna. Simulations of the antennas are carried out using HFSS software and presented here.

Design of microstrip patch antenna using Half-Mode Substrate Integrated Waveguide feeding technique

In this paper, the design of microstrip patch antenna fed by Halfmode Substrate Integrated Waveguide (HMSIW) is presented. The proposed microstrip patch antenna is placed at an inset in the open end of the HMSIW separated by a narrow slot. The HMSIW is excited to generate dominant TE10HM mode. The amount of inset of the patch in the HMSIW helps to get impedance matching and as a result, the incident wave couples easily from HMSIW to patch antenna. The proposed antenna resonates at 10.5 GHz with the bandwidth of 500 MHz (4.76%) and cross polarization level lower than -21dB.

Design of planar substrate integrated waveguide (SIW) phase shifter using air holes

In this paper, a design of Substrate Intergrated Waveguide (SIW) Phase Shifter is designed by placing multiple rows of air holes in a single substrate which modifies effective dielectric constant of the material and as a result, the phase of the propagating wave is modified while maintaining insertion loss less than 0.8 dB. The proposed design operates in X band (8-12 GHz) having reflection coefficient better than -15 dB within a band of 3 GHz (31.5%) and a phase shift of 24.8°±4.7° throughout the operating band.

Design of dual-mode substrate integrated hexagonal cavity (SIHC) filter for X-band application

A Dual-mode substrate integrated waveguide hexagonal cavity (SIHC) filter using hexagonal shaped cavity for X-Band application has been proposed in this paper. Use of perturbation technique to achieve dual mode response has been investigated. The field patterns of the degenerate modes and the mode splitting characteristics are also studied. The theoretical analysis with the help of coupling matrix is shown and experimental verification is also presented.