Exact Design of a New Class of Generalized Chebyshev Low-Pass Filters Using Coupled Line/Stub Sections

Abstract

A complete design theory starting from a distributed generalised Chebyshev low-pass prototype filter is presented. A design example demonstrates excellent performance in good agreement with theory.

Equiripple design of low‐pass filter using stub‐loaded Z‐shaped coupled‐line section

“…Furthermore, the TF (F cir ) is symmetrical, so the field of interest (θ) can be reduced to [0, π/2]. The response in other bands can be obtained simply according to the periodicity, which is a common feature in commensurate line circuits [2,4,5].…”

“…The LPFs in [4,5,[22][23][24][25][26][27] are designed using distributed elements, whereas those in [28,29] are designed using lumped elements with advanced configuration and manufacture capability. [4,5] and our work are designed using commensurate line elements, which simultaneously support low-pass and bandstop response. In addition, the transmission-line-based designs are capable for high frequency up to millimetre wave implementations as that in [27].…”

“…Coupled lines can be widely found in microwave-distributed circuits [1], such as filter [2][3][4][5][6][7][8][9], coupler [10][11][12], phase shifter [13,14] and impedance transformer [15][16][17], due to its controllable coupling strength and ease of planar implementation [1]. In practical circuits, coupled lines appear generally as 'sections', which can be categorized by the number of ports, connecting topology, and ending condition [18].…”

“…The third is well known as the Schiffman unit [13], which can be used for phase equalization [14] or coupling enhancement [12]. By loading the end of the Schiffman unit with an open-circuited stub, a generalized Chebyshev low-pass filter (LPF) can be implemented [4]. Figure 2a shows another two-port CLS configuration, in which two nodes are connected with a uniform transmission line.…”

Investigation on impact of substrate on low-pass filter based on coaxial TSV

“…Eliminating undesired signals, microwave low-pass filters (LPFs) are widely required in modern wireless communication systems. In common, they are realized based on transmission line technology [1], or some novel technologies, such as low-temperature cofired ceramic and liquid crystal polymer processes [2,3]. However, these LPFs suffer from the disadvantages of big size and non-integration.…”