An unbalanced-to-balanced diplexer based on substrate integrated waveguide cavity

Abstract

A novel unbalanced-to-balanced diplexer based on a dual-mode substrate integrated waveguide (SIW) cavity is proposed and implemented. The diplexer is realized using one dual-mode cavity and two single-mode cavities. By properly choosing, feeding and coupling the cavity operating at the TE 102 or TE 201 mode, so as to not only provide capabilities to realize the desired unbalanced-to-balanced transmission within both Rx and Tx channels but also realize good differential-mode channel-to-channel isolation. To the author's knowledge, we present for the first time an unbalanced-to-balanced type diplexer based on the application of SIW. The proposed diplexer was successfully designed, simulated, and fabricated. Good agreement can be observed between simulated and measured performances in our letter. The measured in-band common-mode rejection is better than 33 dB for both channels. A minimum differential-mode isolation of about 50 dB across the Rx band and about 40 dB across the Tx band is also observed in the measurement.

Self-diplexed antenna based on loading asymmetric grounding-vias

“…In the past few years, diplexing wireless communication systems have been greatly developed due to the provided extra functionality and compactness . In particular, transmitting and receiving signals from uplink and downlink channels, respectively, are in adjacent frequency bands.…”

“…In the past few years, diplexing wireless communication systems have been greatly developed due to the provided extra functionality and compactness. [1][2][3][4] In particular, transmitting and receiving signals from uplink and downlink channels, respectively, are in adjacent frequency bands. The key component of a conventional diplexing communication system is the diplexer, a three-port device connecting the transmitter and receiver to the common antenna, as shown in Figure 1.…”

Balanced and unbalanced diplexers design using substrate integrated waveguide cavities

“…The SIW is very suitable for designing diplexers, as it avoids the waveguide's bulkiness and high fabrication cost but still preserves the versatility and flexibility of the substrate. Since then, several noteworthy works have been reported . Nowadays, balanced configurations have been widely adopted in microwave front‐end circuits because of their nice noise‐resistant properties.…”

Flexible design procedure for realisation of dual‐mode substrate integrated hexagonal‐cavity‐based diplexer

“…However, this multilayer fabrication technique leads to fabrication complexity and poor response in terms of insertion losses in the passband of both the channels. An unbalanced-to-balanced diplexer is reported in [10] where one rectangular dual-mode cavity is utilised as a common resonator and a rectangular single-mode cavity is adopted in each Rx and Tx channels. In the input, dual-mode resonator helps to improve the isolation between Rx and Tx channels.…”