Chandra Shekhar Prasad

Broadband Planar Transition to Dielectric Image Line by Substrate Truncated Microstrip Line for Millimeter-Wave Circuit Integration

In this letter, a broadband planar substrate truncated tapered microstrip line-to-dielectric image line transition on a single substrate is proposed. The design uses substrate truncated microstrip line which helps to minimize the losses due to the surface wave generation on thick microstrip line. Generalized empirical equations are proposed for the transition design and validated for different dielectric constants in millimeter-wave frequency band. Full-wave simulations are carried out using high frequency structural simulator. A back-to-back transition prototype of Ku-band is fabricated and measured. The measured return loss for 80-mm-long structure is better than 10 dB and the insertion loss is better than 2.5 dB in entire Ku-band (40% impedance bandwidth).

Planar Excitation of Dielectric Waveguide Antenna for Broadband and High Gain Application

In this letter, a linearly tapered dielectric waveguide antenna with planar substrate integrated waveguide (SIW) feeding is presented for Ku-band (12–18 GHz) application. To make the feeding network planar, the SIW and central part of antenna are fabricated on a single substrate. Two metal strips are mounted on each top and bottom side of the central part of the antenna element for matching purpose. The antenna is designed and optimized using Ansoft HFSS. The optimized prototype is fabricated and measured. An endfire radiation pattern is achieved with low sidelobe (around 12 dB) and cross-polarization (around 20 dB) level in both E- and H-planes. The measured impedance bandwidth and maximum gain are 33.3% (11.5–16.1 GHz) and 12.4 dBi, respectively.

A high gain aperture coupled cylindrical dielectric resonator antenna with metamaterial superstrate

This paper presents a design of high gain cylindrical dielectric resonator antenna (CDRA) with the help of metamaterial superstrate. A double layered metamaterial superstrate with unit cell periodicity of 4×4 is designed and suspended above a CDRA. The height of metamaterial superstrate from the ground is optimized to enhance the gain of antenna. The CDRA is fed by microstrip through aperuture at the ground plane. The gain of CDRA with metamaterial superstrates is found to be increased by 4.1 dB and the impedance bandwidth is al so improved.

Effects of coaxial probe dimensions on broadband transition to substrate integrate waveguide

The effect of probe dimensions on the excitation of substrate integrated waveguide (SIW) in thick substrate in X (8- 12 GHz) and Ku (12-18 GHz)-frequency band is presented. The SIW is excited by a standard SMA connector and with K-connector and their performances are compared. The proposed transition is simulated using Ansof HFSS. The simulated bandwidth (S11<; -20dB) for standard SMA-to-SIW back-to-back transition is 38.65% and for the K-connector-to-SIW back-to-back transition it is improved up to 61.81%.

Dual-beam dielectric image line tapered antenna in planar environment

A dual-beam antenna designed using tapered dielectric image line (DIL) in Ku-band (12-18 GHz) is presented in this paper. The antenna is fed centrally by probe fed substrate integrate waveguide (SIW) power divider made on same substrate which makes the design fully planar. The proposed antenna is simulated by using Ansot HFSS. The proposed antenna provides two main beam directed at 72° and -72° from broadside almost independent of frequency throughout the operating band. The maximum gain achieved is 12.2 dBi in both main beam directions and the impedance bandwidth (S11<; -10 dB) is 41.8% (13.6-20.8 GHz). The proposed antenna also provides good cross polarization level in both E and H-plane.