Frequency and bandwidth tunable reliable MEMS bandpass filter for 24 GHz radar applications

Abstract

In this work, radio frequency (RF) micro-electromechanical system (MEMS)based frequency and bandwidth tunable bandpass filter is presented for application in 24 GHz Doppler radar transceivers. The filter is fabricated on 635 μm alumina substrate using surface micromachining process. Total area of the filter is only 2.8 mm 2 excluding bias lines and pads. Functional building blocks of the proposed filter are fabricated and tested independently to ensure optimum filter responses. The proposed filter can be tuned to any frequency between 22 and 24 GHz based on electrostatic actuations. It demonstrates insertion loss of 1.67 dB and matching of 18.6 dB at 24 GHz with fractional bandwidth of 6.5%. Filter gives acceptable matching over a 5 GHz bandwidth (21.65-26.65 GHz) with an average insertion loss of 4.7 dB. Filter works satisfactorily up to 10 billion cycles with 0.1 to 1 W of RF power. To the best of our knowledge, this is the first reported tunable MEMS bandpass filter at 24 GHz with 10 billion cycles reliability and with 1 W of RF power for radar applications.

Investigation on temperature stability of MEMS silicon‐based sixth‐order stripline filter

“…Table 2 shows the comparison between the designed BPF and other different technologies of BPF (such as printed circuit board (PCB), 10,[19][20][21][22] complementary metal oxide semiconductor (CMOS), 23,24 SiGe, 25,26 GaAs, 27,28 and MEMS [29][30][31][32] ). It can be seen from Table 2, the proposed filter has a smaller size compared to the PCB filter, better return loss, and out-of-band suppression performance compared to the CMOS, SiGe, and GaAs filter.…”

New Design Approach for the Dual-Band Bandpass Microwave Filter (DBBPF) Inspired by Square Symmetrical Metamaterial Resonators (SSRRs) for X- and Ku-Band Applications

“…Microwave filters have proven day after day their importance and their influence on modern telecommunication systems. For multi-band applications, the microwave bandpass filter becomes a main component [1][2][3][4] because of the electrical qualities offered by this filter. The operation on several frequency bands for a single operator requires several circuits in the same system, which makes it voluminous with considerable interference, so the use of a multiband filter becomes a necessity to solve this problem.…”

A dualband bandpass filter with tunable bandwidths for automotive radar and 5G millimeter-wave applications

“…On the other hand, the development of autonomous driving systems and the rising of government policies for vehicle safety have led to considerable growth of automotive radar technologies in recent years [3]- [7]. Hence, bandpass filter (BPFs) will significantly impact the overall system performance [8]- [10], and the multiband function is preferred since applications are evolving daily [11]- [13]. However, these filters should be compact to ease their integration with other radiofrequency (RF) components, highly selective, deep transmission zeros around the passbands, and low insertion loss [11].…”