In this paper, millimeter-wave bandpass filters with λg/4 short stubs made by surface micromachining on a GaAs substrate are presented. These filters show flexible bandwidth by variation of the position of the short stub using the external quality factor, Q e without changing the impedance value at millimeter-wave range. The bandpass filters can be realized with a wide (50%) or narrow (10%) bandwidth simply by adjusting the positions of the short stubs. They show insertion losses of 2.3 and 6.8 dB, and return losses of 15 and 16 dB, respectively at a center frequency of 60 GHz.

In this article, a broadband double-balanced mixer is

In this paper, a novel tunable bandpass filter with an improved J‐inverter is suggested. In this resonator, as the loading capacitance is increased, the resonant frequency is decreased. Also, the phase of the admittance inverter has characteristics that are variable by series capacitors and parallel varactor diodes. The electrical length of the inverter always maintains 90° at a given physical length of the inverter, which should be changed for different operating frequencies. This new bandpass filter has a tuning range of 1.8 GHz ∼ 2.45 GHz and an insertion loss of less than 2.5 dB. Also, the bandwidth is almost constant within the tuning range. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:852–855, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27467

In this paper, a novel ultra wideband (UWB) bandpass filter is presented using stepped-impedance resonator and vertical coupling structure. This filter configuration is presented with bandwidth up to 135.8 percent covering the 2.2 -11.5 GHz range. Excellent stopband performance is obtained up to 17.7 GHz. They show the insertion loss of 1.8 dB and return loss of 14 dB at the center frequency 6.85 GHz.

In this paper, a new microstrip stepped‐impedance hairpin resonator with interdigital capacitor (IDC) slow‐wave band‐pass filter (BPF) using dielectric supported air‐gapped microstrip line (DAML) of surface micromachining on GaAs substrate is proposed. Unlike conventional slow‐wave filters, the proposed bandpass filters are designed to produce a narrow passband at the fundamental mode of the resonators with small size and a sharp skirt characteristic. The proposed slow‐wave band‐pass filter with IDC is designed to produce a passband of 7.7% at the fundamental frequency of 56 GHz. It shows insertion loss of 3.37 dB, return loss of better than 15 dB, and a stopband characteristic greater than 31 dB within 37.03–45.51 GHz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1244–1247, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21667