Design and Development of a Uniplanar a 3-dB Hybrid Coupler for Microwave Integrated Circuit Applications

This paper presents the design of a uniplanar 3-dB hybrid coupler for microwave integrated circuits (MIC) and monolithic MIC (MMIC) applications. The same was developed and tested experimentally using a network analyzer in Sumeru Microwave Communication Lab. Its design and application issues have been widely discussed here with some standard data and graphs. The experimental results for the standard 1.5λ circumference uniplanar 180° hybrid-ring coupler has been found in the standard accuracy range of 3.2 ± 0.4 dB coupling, isolation found is greater than 30-dB and the return loss better than 18.2-dB over a 2% bandwidth centered at 1.46 GHz. Also the experimental insertion loss found for this passive component is 0.5 dB at 1.46 GHz. The same has been concluded with its futuristic perspectives for research aspirants and microwave engineers.

I. INTRODUCTION

The ever increasing endless number of applications in MIC and wireless communication, the parameters like bandwidth, efficiency, gain and fabrication cost play very important role to select and design compatible hybrid couplers with improved performance. Hybrid ring is a part of feed in tracking type of antennas which use amplitude comparison mono-pulse technique. In this technique the RF signal received from offset antenna beams are combined so that the sum and difference signals are obtained simultaneously. The sum and difference signals are multiplied in phase sensitive detector to obtain both the magnitude & direction of error signal.