Dual‐band dual‐polarized microstrip antenna at S‐ and X‐bands using feed technique for suppression of interference due to higher order modes

Abstract

This paper presents a novel configuration for dual band dual polarized (DBDP) microstrip antenna (MSA) at S-and X-bands. The antenna at S- and X-bands with high frequency ratio between the two bands utilizes the proposed configuration which uses the MSA at S band as ground for 2 × 2 MSA array at X-band, thereby making it compact. It simultaneously achieves better gain, bandwidth, radiation pattern stability and good isolation. The proposed DBDP antenna configuration overcomes the issue of interference between higher order mode due to first frequency with second frequency using proposed feed technique. It uses electromagnetic coupling (EMCP) technique to give measured bandwidth ( ∣ S 11 ∣ ≤ −10 dB) from 2.3 to 2.6 GHz ( 12.2 %) at S band and from 7.8 to 8.3 GHz (6.2%) at X-band. The measured isolation between the two orthogonal ports is better than 28 dB at 2.5 GHz and 32 dB at 8.2 GHz. The gain at 2.5 GHz is 7.4 dBi and at 8 GHz, it is 10 dBi. Such an antenna can be used for telemetry, tracking and command application in satellite communication, etc.