Topic
Balun
About: Balun is a research topic. Over the lifetime, 5375 publications have been published within this topic receiving 52256 citations. The topic is also known as: Telephone balance unit.
Papers published on a yearly basis
Papers
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TL;DR: In this article, a low-length (10 mm) frequency-independent (4.5 GHz) beamforming balun was proposed for planar log-periodic dipole array antenna (PLPDA).
Abstract: A new balun used for feeding a planar log-periodic dipole array antenna (PLPDA) is proposed. This balun, which is based on mode conversion, converts gradually the transmission mode from quasi- TEM (coaxial cable) to full TEM (balanced line), with an accessible excitation current property (ECP), which is not achievable in classical feeding techniques (infinite or self balun). To validate this approach, an ultra-wideband (UWB) PLPDA antenna was designed with these balun structures for operating in the L and S bands (1-4 GHz) and the results were compared in terms of reflection coefficient and radiation pattern. A PLPDA antenna with a mode converter balun was fabricated. Results show that the proposed balun is a low length (10 mm) frequency-independent (4.5 GHz based on |S11|<-10 dB) device useful for feeding the UWB PLPDA antenna. Moreover, antenna's ECP can be modified, which is necessary for phase centre variation compensation.
21 citations
TL;DR: In this article, the effect of even-mode open-circuit termination on the output waveforms of push-pull power amplifiers (PAs) is measured and a novel mathematical formulation is proposed to describe the time-domain waveforms by defining the harmonic impedance environment in terms of odd and even mode excitation rather than tuned harmonics.
Abstract: Push-pull power amplifiers (PAs) operating at HF through to GHz frequencies typically employ a transmission line balun structure. This letter demonstrates that their performance characteristics in high efficiency PA applications are critically different from conventional transformers. For the first time, the effect of the even-mode open-circuit termination on the output waveforms is measured. A novel mathematical formulation is proposed to describe the time-domain waveforms by defining the harmonic impedance environment in terms of odd and even mode excitation rather than tuned harmonics. Experimental verification using harmonic load-pull measurements showed good agreement with the theoretical waveforms generated from factorized waveform expressions.
21 citations
TL;DR: In this paper, a high-power terahertz solid-state amplifier fabricated using 0.25 μm InP heterojunction bipolar transistor (HBT) technology is reported.
Abstract: A high-power terahertz solid-state amplifier fabricated using 0.25 μm InP heterojunction bipolar transistor (HBT) technology is reported. This amplifier utilies a novel defective-ground four-way balun to combine differential amplifier chains for a total output device periphery of 40 μm. A significant amount of power of ∼10 mW is obtained at 305 GHz with better than 20 dB small-signal gain.
21 citations
TL;DR: In this paper, three different equivalent circuits (asymmetric, symmetric, and mixed) of the 90° coupled transmission-line sections are proposed for Marchand baluns, including the accurate modeling of the effect of the connecting segment.
Abstract: Three different equivalent circuits (asymmetric, symmetric, and mixed) of the 90° coupled transmission-line sections are proposed for Marchand baluns, including the accurate modeling of the effect of the connecting segment. The asymmetric one consists of one set of coupled transmission-line sections and two identical uncoupled transmission-line sections. Due to the asymmetry and a four-port circuit configuration, it seems to be difficult to derive the design formulas for the asymmetric equivalent circuit, thus leading to their indirect derivation by adding two identical transmission-line sections with effectively “negative” electrical lengths to the original 90° coupled transmission-line sections. The symmetric one may be obtained by combining the even- and odd-mode equivalent circuits, while the mixed equivalent circuit is combining the asymmetric and the symmetric ones. As a proof-of-concept, a symmetric and an asymmetric equivalent circuits along with a Marchand balun with a connecting section were implemented at 2 GHz, demonstrating a very good agreement between the simulated and the experimental values.
21 citations
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TL;DR: In this article, a front end module is arranged as a module using an antenna switch (6), a low pass filter (5 ), a surface acoustic wave filter (7 ), and a balun (8) integrated by a multilayer substrate.
Abstract: Such a front end module is arranged as a module using an antenna switch ( 6 ), a low pass filter ( 5 ), a surface acoustic wave filter ( 7 ) and a balun ( 8 ) integrated by a multilayer substrate ( 11 ) and components incorporated in or mounted on the multilayer substrate ( 11 )
21 citations