Synthesis of Dual-Band Bandpass Filters With Short-Circuited Multiconductor Transmission Lines and Shunt Open Stubs

Abstract

The design of dual-band bandpass filters consisting of series short-circuited wire-bonded multiconductor transmission lines and shunt open stubs is thoroughly carried out in this paper. Two different configurations are studied, and closed-form analytical design equations are derived to synthesize Chebyshev filtering functions. A novel, simplified, and time-saving synthesis procedure to design dual-band filters with narrow or moderate broad bandwidths is finally presented, attending to the required final specifications and the physical and manufacturing limitations. The usefulness and validity of the proposed analytical equations are illustrated by designing, manufacturing, and measuring three different prototypes, showing an excellent agreement between analytical and measured results. INDEX TERMS Bandpass filter, Chebyshev response, coupled lines, dual-band, multiconductor transmission lines (MTLs), shunt stubs.

Dual-Band Continuous Class-F−1 Power Amplifier With Second-Harmonic Suppression for Harmonic Radar Systems

“…A band-pass or band-stop filter allows only a specific frequency range to pass through while blocking other frequencies. One approach to constructing a band-pass or band-stop filter involves combining a series transmission line with an open stub to create various band-pass filters [18,19]. We introduce the HCDMN to move the load impedance to optimal matching points at two frequencies and suppress the second-harmonic frequency range for multiband harmonic radar transmitters simultaneously.…”

Analytical Design of Compact Multiband Bandpass Filters with Multiconductor Transmission Lines and Shunt Open Stubs

“…This is only possible as the coupled lines are alternately interconnected with wire bondings to eliminate undesired TEM (transverse electromagnetic) modes inherent to multiconductor structures. In this sense, MTLs have been successfully used for synthesizing wide and ultra-wideband differential [9] or dual-band bandpass filters [10]. Specifically, in ref.…”

“…Specifically, in ref. [10], a procedure for the synthesis of Chebyshev-type filters designed from a dual-band transformation was proposed [11], where both bands have the same bandwidth.…”

“…It is noteworthy that, with this configuration, filter parameters can be controlled by varying the even and odd mode impedances and the electrical lengths of the MTLs and the stubs. This structure, compared with [10], introduces the independence of the selected bands. Furthermore, it presents a very straightforward design procedure if examined with other previous works [12], taking advantage of the intrinsic multiconductor frequency response.…”

Compact Wide-Frequency Tunable Filter With Switchable Bandpass and Bandstop Frequency Response

“…Bandpass and bandstop filters are widely used in microwave and millimeter-wave circuits and systems due to the ability of selecting or suppressing signals at specific frequencies [1]- [12]. Over the past years, great attentions have been paid to tunable/reconfigurable filters based on various circuit structures, owning to their applications to reduce the complexity and strengthen expansibility in modern electronic systems [13]- [22].…”