A Simple WiMAX and RFID Band-Notched UWB Bandpass Filter and Its Susceptibility Study

Abstract

An ultra-wideband (UWB) bandpass filter (BPF) with a fractional bandwidth (FBW) of about 110%, transmission zero at the high-frequency edge, and band notches at the worldwide interoperability for microwave access (WiMAX) and radio frequency identification (RFID) band is presented in this paper. The filter is based on single short-circuited stub, U-shaped defected ground structure (DGS) array, two U-shaped resonators and two stepped impedance resonators (SIRs). The filter is compact and exhibits a selective filtering characteristic equivalent to a three-pole Chebyshev filter. The design procedure has been described and verified by full-wave electromagnetic (EM) simulation and measurement. The proposed filter has low insertion loss, sharp rejection, and excellent in and out band performance. Due to its applications in WiMAX and RFID systems, the filter may be subjected to high EM radiation from the antenna and nearby sources. Therefore, susceptibility study of such a filter is very important. Hence, the susceptibility study of the band-notched UWB BPF has been carried out by subjecting the structure to an interference source.

Design of double-notch UWB filter with upper stopband characteristics based on ACPW-DGS

“…As can be seen from the second column of Table 6 , the filter in this paper is different from others in structure, it adopts the improved ACPW-DGS. It can be seen from the third column that the structure proposed has transmission zeros in both the upper and lower passbands unlike the [ 5 , 37 , 42 , 44 ], which has only one transmission zero, whereas [ 38 , 41 , 43 ] do not possess transmission zero. Columns 4, 5, and 6 describe that the structure in this design has a relative bandwidth of 3dB of 110%, the return loss is greater than 12.15dB, and there are two notches at 9.28GHz and 10.48GHz, all of which are greater than 20dB.…”

“…Compared with other filter designs, the filter has the following advantages in physical processing: no complicated processing technology is required, no drilling is required, and the dimensional accuracy of the board design is after one decimal point. The UWB filter designed in this manuscript is compared with the [3,5,[33][34][35][36][37][38][39][40][41][42][43][44], and the results are shown in Table 6. As can be seen from the second column of Table 6, the filter in this paper is different from others in structure, it adopts the improved ACPW-DGS.…”

Compact quintuple notched-band UWB BPF with high selectivity and wide bandwidth

“…Ultra-wideband (UWB) bandpass filter (BPF), as one of the key component in the UWB system, influences the overall system performance [1]. A number of UWB BPFs have been reported using different methods and structures: optimum short-circuited stubs [2], stepped impedance resonator (SIR) [3], multiple-mode resonator (MMR) [4, 5], etc. However, coexisting wireless services in the UWB frequency spectrum may cause potential interferences, such as WiMAX (3.4–3.6 GHz), wireless local area network (WLAN) (5.15–5.35 and 5.725–5.825 GHz), C-band satellite communication services (CSCS) (6.425–6.725 GHz), X-band satellite communication services (XSCS) (downlink: 7.25–7.75 GHz, uplink: 7.9–8.395 GHz), ITU-8 band (8.3–9.1 GHz), and radio navigation (RN) band (9.3–10.6 GHz).…”