Cylindrical Dielectric Resonator Antenna Excited by a Composite Feed to Generate Monopole Like Radiation Characteristics

Abstract

In this paper, a monopole like single segment cylindrical dielectric resonator antenna (CDRA) with a composite feed (probe with microstrip patch feed) configuration is described. The antenna consists of liquid phase (3 wt.% 45Bi2O3-55B2O3 glass) sintered Ba0.5Sr0.5TiO3 dielectric ceramic (BST-BB3) having dielectric constant (er) of 17 as a radiating element of CDRA. 3 wt.% 45Bi2O3-55B2O3 glass reduces the sintering temperature of Ba0.5Sr0.5TiO3 from 1250°C to 950°C without affecting the crystal structure and thereby reduces the manufacturing cost of the ceramic material. Three different feed configurations i.e. probe connected to plus-shaped patch (PPP), probe connected to swastika-shaped patch (PSP) and PXP [probe connected to XOR-shaped patch] are proposed. The simulated field distributions show that TM01δ, TE01δ and distorted TM01δ modes are excited as dominant modes in PPP-, PSP-, and PXP-fed CDRA respectively. The simulated − 10 dB reflection coefficient bandwidths of the CDRA excited by three different feed configurations are compared. CDRA with PXP feed (proposed antenna) provides largest − 10 dB reflection coefficient bandwidth of 40.77% (7.44–11.25 GHz) with resonant frequency of 7.78 GHz. The experimental − 10 dB reflection coefficient bandwidth of the proposed antenna is found to be 52.08% (7.03–11.98 GHz) with resonant frequency of 8.30 GHz. The proposed antenna provides monopole like stable radiation patterns which get distorted towards higher frequency side of the operating frequency band. The experimental reflection coefficient–frequency characteristic as well as radiation characteristics of the proposed antenna are nearly in agreement with the corresponding simulated characteristics. The proposed antenna can find potential application in radar and communication.