Design of Reconfigurable Miniaturized Uwb-BPF With Tuned Notched Band

Abstract

Abstract-A new miniaturized ultra-wideband bandpass filter with embedded reconfigurable multiband frequency notch function was designed and implemented by embedding all the passive components into a printed circuit board with a high dielectric constant. The proposed filter consists of compact 2U-shaped DGS resonators shunt connected to parallel coupled lines to achieved frequency notch. To tune the notched band, suitable capacitor elements within the inner/outer U-DGS and RF PIN diode within the outer U-DGS are integrated. A curve fitting formula is derived to show the effect of the capacitor value on the center frequency of the notched band, which is decreased by 56.7%. These capacitors improved the quality factor and have the effect of reducing the filter size by 72% as compared to other filters. The RF PIN diode in the outer U-DGS acts as a switch to exhibit a band notch covering the bandwidth of the WLAN for IEEE 802.11 a/h at 5.5 GHz and RFID ISO 18000 series pars 5 in microwave (MW) which is set at 5.8 GHz, 6.1 GHz and 6.8 GHz, and the other bands. RF PIN diodes control the notched band and raises it from 5.25 GHz to 6.85 GHz (27%) or remove the band notched according to its positions. In order to validate the feasibility of the proposed structure, UWB BPF with center frequency of 6.85 GHz is designed, fabricated, and measured. The filter has passband from 3.2 GHz to 10.7 GHz and notched band designed to generate stop band from 5.25 to 6.85 GHz, and the two transmission zeros are observable at 2 GHz and 12.5 GHz, respectively by measurement. This paper shows the miniaturized filter with size 6.7 mm × 6.5 mm occupying a circuit area of about 0.41λ g by 0.39λ g . The measured results for the proposed filter are in good agreement with simulations and verify the excellent performance of the designed filter and the validity of the proposed approach.

Tunable Filtenna With DGS Loaded Resonators for a Cognitive Radio System Based on an SDR Transceiver

“…In this section, two coupled DGS resonators and a bandpass filter are introduced. The DGS is etched in the ground plane to produce current distributions which affect the capacitance and the inductance of the transmission line which enables it to operate as a combined bandstop / bandpass filter [24]- [26]. The center frequency is shifted from 2.85 GHz, 2.45 GHz and 2.05 GHz when the capacitance values are changed to 0.6 pF, 1 pF and 1.5 pF respectively.…”

LPF/dual-BPF/UWB-BPF reconfiguration utilizing DGS resonators and lumped capacitors

“…Recently, many tunable filters have been reported such as the reported Band stop filter (BSF) in [15] which is based on a tunable epsilon-shaped metamaterial using a lumped capacitor (connected in series) to achieve triple-band operation, also the same kind of lumped capacitors (connected in shunt) can shift the obtained bandpass behavior to the lower-frequency range causing a reduction in the filter size to more than 35% as in [16]. The reconfigurability of the suggested filters in [17, 18] is carried out using PIN diodes to either obtain dual-mode behavior or control the notched band, respectively.…”

A compact UWB band-pass filter with a notch band using multi-mode stub-loaded resonators (MM-SLR)

“…A new UWB BPF using triangle-ring multi-mode stub-loaded resonator (MM-SLR) was presented in [8], so that there are five resonant modes generated in the UWB pass band, including two odd modes and three even modes. Design of reconfigurable miniaturized UWB BPF with the tuned notched band was reported in [9], consisting of compact 2U-shaped defected ground structure (DGS) resonators shunt connected to parallel coupled lines to achieved frequency notch. An UWB BPF with a notch band at 5.8 GHz and wide stop band using dumbbell stubs were propounded in [10], which constructed with multiple-mode resonator (MMR) using novel dumbbell stubs and one-arm-folded interdigital coupled lines in the input and output sides.…”