Stopband-Extended Balanced Bandpass Filter Using Coupled Stepped-Impedance Resonators

Abstract

A novel fourth-order balanced bandpass filter is proposed based on the half-wavelength ( 2) stepped-impedance resonators (SIRs). By properly adjusting the parameters of each SIR, the proposed filter may be made compact and its stopband may also be extended simultaneously. Specifically, a balanced filter with acceptable common-mode rejection is implemented with its differential-mode and common-mode stopbands extended up to 5.5 0 , where 0 is the center frequency of differential-mode passband.

Dual-Band Differential Filter Using Broadband Common-Mode Rejection Artificial Transmission Line

“…This procedure allows for the design of differential filters by simply using standard techniques for the differential response without paying attention to the common-mode behavior. Then, there is no need to develop specific simultaneous solutions for both common-mode suppression and differential-mode specs [1][2][3]5]. This technique has been successfully applied to design single-band bandpass filters [14,15], for which a relatively narrowband common-mode rejection device is sufficient.…”

“…Ideally, differential signal transmission methods meet the tight requirements of EMI compliance and signal integrity but, in practice, any differential signal has some level of common-mode noise (mainly caused by amplitude unbalance and time skew). Since this common-mode level can lead to undesired radiation and EMI problems that degrades the performance of high-speed circuitry, a lot of effort has been devoted to the design of differential devices with high common-mode rejection [1][2][3][4][5][6][7][8]. A different approach to achieve good performance is to combine artificial transmission lines providing good common-mode suppression (while keeping the integrity of the differential path) with differential devices (such as bandpass filters) whose common-mode response might not be satisfactory.…”

Very Compact Full Differential Bandpass Filter With Transformer Integrated Using Integrated Passive Device Technology

“…In [14], researchers used coupledline sections and quarter-wavelength (λ/4) resonators to design a full differential bandpass filter but its area still needs further reduction. A stepped-impedance resonator (SIR) is another proposed method for full differential bandpass filter design [15]. A coupled-resonator and half-wavelength (λ/2) resonator were used in [16,17], while a doublesided parallel-strip line (DSPSL) dual-mode resonator was proposed in [18].…”

Balanced Single- And Dual-Band BPFS Using Ring Resonators

“…In the past few years, balanced BPFs have received increasing attention [2][3][4][5][6][7][8][9][10][11][12]. These balanced BPFs have been constructed using coupled-line structures [2,3], branch-line structures [4,5], and, for the most part, multi-section resonators [6][7][8][9][10][11][12]. Each of these multi-section resonators does not form a closed loop and hence can be referred to as an open-loop resonator.…”

“…Similarly, closed-loop resonators, alternatively called ring resonators, have been widely employed to build single-ended BPFs as well [18][19][20][21][22][23][24][25]. Although open-loop resonators have also been frequently used to construct balanced BPFs, from singleband [6,7] to dual-band ones [8][9][10][11][12], so far closed-loop resonators have not yet, however. Hence, the purpose of this paper is to show that closed-loop resonators can also be employed to design new balanced BPFs in a clever manner.…”