A Compact Reconfigurable 1-D Periodic Structure in GaAs MMIC With Stopband Switching, Dual-Band Operation and Tuning Capabilities

This paper presents a systematic study of a compact and reconfigurable periodic structure in GaAs MMIC technology. Compactness is achieved by the introduction of spiral inductors in a conventional unit cell without disturbing the reactive loading mechanism. The proposed architecture exhibits a 28.3% wider stopband with 62.6% smaller footprint compared to a conventional structure. The compactness and bandwidth improvement in the proposed structure is explained with the help of dispersion and circuit analysis. The reconfigurability built into the design using PIN diodes allows stopband switching, dual-band operation and tuning capabilities with the mere use of a single reactive load in its unit cell. To the best of the authors knowledge, it is the first time a reconfigurable MMIC implementation is realized using the proposed structure or even the conventional design. As a guide to design, sensitivity analysis to filter performance is presented for important structure parameters. Switching element parasitics are discussed in two ways: firstly, with the design and measurement of structures with idealized switching conditions and in second, with the circuit and full-wave EM modelling of the finite periodic structure with the actual PIN diodes. The on-chip measurements of the fully reconfigurable filter show excellent agreement with simulations.