Microstrip wideband bandstop filter with open stubs for UWB applications

Abstract

This article describes the development of an optimized microstrip wideband bandstop filter (BSF) with open stubs for ultrawideband applications. Simulated results agree with the measured results, demonstrating in the experimental results a 10 dB bandwidth from 4.6 to 7.6 GHz, insertion loss (S21) of −33.9 dB, and minimum return loss (S11) of −0.40 dB at 6.1 GHz. Additionally, an equivalent circuit of the wideband BSF is built to estimate the electromagnetic simulation results for practical realization. The features of the design have a reduced size, wideband rejection, higher insertion loss, and tunable bandwidth, which can be performed by adjusting the L‐shaped stubs (0.41λg and 0.29λg) toward the 50 Ω input and output ports. The designed BSF occupied the size of 0.35λg × 0.29λg. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1003–1006, 2015

Miniaturized dual‐band bandpass filter based on stepped impedance resonators

“…These resonators are coupled by the coupling capacitor, C 3 . These resonators are coupled in parallel while C p1 , C p2 in Port 1 and Port 2, respectively show the parasitic capacitances between the substrate and ground [2,3]. Even if the overall equivalent LC components have some effects on the resonation, the lower band represented by the series resonator, L 2 and C 2 , has the center frequency of 2.4 GHz while the higher band represented by the series L 3 and C 4 has the center frequency of 3.8 GHz.…”

“…Many microwave designers are actively studying such filters to achieve compact size, better performances, and low cost. At the same time, the demand for wideband data processing, such as voice and multimedia, is also rapidly increasing [1][2][3][4][5]. In the DB-BPF design, stepped impedance resonators (SIRs) have been widely used.…”

“…A typical CMOS RF PA generally suffers from low breakdown voltage and poor linearity because of the AM-PM distortion caused by nonlinear junction capacitance of the CMOS FETs [1][2][3][4][5]. Various linearization techniques have been investigated to improve the PA linearity, such as phase injection [1], dynamic gate bias control [2], feedback [3], and so on. These works successfully compensated the nonlinearities for 3G W-CDMA, even 4G LTE applications, showing acceptable ACLRs.…”

“…However, for future communication standards, such as LTE-advanced, the uplink PA is required to support intraband contiguous carrier aggregation signal whose operating bandwidth (BW) is expanded up to 40-MHz without compromising the ACLR specification. The previous linearization techniques [1][2][3] are limited to only 10-MHz LTE bandwidth operation, so the development of the wideband linearizer that supports 40-MHz BW LTE-A application is urgently needed. In this work, a linear CMOS RF PA with an integrated…”

Miniaturized Multi-spurline Bandstop Filter Design with a Meandered Slot Lines

“…The trend of using different types of bandstop filters such as stepped impedance resonators (SIR) bandstop filter, split ring resonators (SRR) filter, bandstop filter with spiral resonators, hairpin resonators, spurline resonator filters, meandered slot line resonator bandstop filters, wideband bandstop filters and so on. These filters can be used for the transmitter and receiver of the wireless communication systems [2][3][4][5][6][7]. Therefore, many researchers are making an effort to enhance the performance of bandstop filters with different patterns with stable S-parameter responses.…”