A Packaged MISL Dual-Band Unequal-Order Bandpass Filter Using Hybrid Resonant Cells

Abstract

In this paper, we present an unequal-order bandpass filter (BPF) using packaged multilayer metal-integrated suspended line (MISL) technology. Our proposed multimode hybrid resonant cells combine high-$Q$ patches and slotline modes, allowing for the achievement of three independent controllable frequencies and compact sizes. The key advantage of this resonator is the ability to collect and utilize different resonance modes, enabling the design of unequal-order dual-band BPFs. To validate the effectiveness of the proposed concept, a series of filters with unequal orders were simulated. Additionally, a filter (third-order for the first passband and sixth-order for the second passband) was designed, simulated, and tested. The test results demonstrated that the unequal-order filters proposed by us possess advantages of wide bandwidth, low loss, and unequal-order filtering responses.