Design of a narrow dual‐band BPF with an independently‐tunable passband

Abstract

Using polygonal resonators and bended lines, a new type of dual-band bandpass filter (BPF) is presented generating a fixed passband centred at 2.70 (f 01) and an independently-electronically tunable passband (f 02) which can be tuned between 3.65 and 6.51 GHz (56% tuning range). The measured results indicate that the return losses of both passbands are >21 dB throughout the tuning range. Furthermore, the use of bended lines leads to extremely small size of 0.136 × 0.098l 2 g , where l g is the guided wavelength at the lowest working frequency (f 01). The proposed BPF also benefits from an ultra-wide upper stopband from 7.03 up to 14.41 GHz (based on 21 dB points), suppressing unwanted signal by more than 21 dB considered as a positive point. The filter prototype is investigated in four design stages with the LC analysis to support the design process theoretically and fabrication results to validate the design practically.

New design of an adjustable compact microstrip lowpass filter using Z‐shaped resonators with low VSWR

“…It should be noted that two rectangular lines with the width of d1 are connected to the input and output ports in order to match the impedance to 50 Ω. The width of d1 can be derived using the formulas explained in 1 . The dimensions of the basic resonator are as follows: d1 = 1.18 mm, d2 = 2.3 mm, d3 = 3.75 mm, d4 = 5.85 mm, d5 = 0.9 mm, d6 = 4.7 mm, d7 = 1.7 mm, d8 = 1.1 mm, d9 = 5.90 mm, d10 = 4 mm, d11 = 2 mm, d12 = 2.48 mm, d13 = 0.1 mm, and d14 = 3.8 mm.…”

“…Owing to the essential role of microstrip devices in modern wireless communication systems, diverse structures have been suggested to design microwave circuits. Microstrip filters due to their duty in suppressing unwanted harmonics have received more attention 1,2 among which bandpass filters and lowpass filters (LPFs) are at the center of attention.…”

Design and fabrication of a miniaturized Gysel power divider using improved T‐shaped resonator

“…In the last decade, researchers have concentrated on using bandpass filters [8][9][10][11][12][13] and lowpass filters [14][15][16][17][18][19][20][21] as an effective method to produce a high-performance Gysel power divider. In refs.…”

A New Reflectionless Filter Composed of Discharging Circuit

“…At the same time, different dual-band bandpass filters with excellent performance and compact size are in tremendous demand with the rapid growth of various wireless communication systems. Recently, many scholars have designed dual-band bandpass filters [7][8][9][10][11][12][13][14][15][16][17][18][19] and reflectionless dual-band bandpass filters (RDBPFs) [20][21][22][23][24]. Thus, this work presents a new reflectionless dual-band bandpass filter based on this method proposed in this paper.…”