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 paper, the design of coupled spiral transmission-line baluns modeled after the Marchand type is discussed, and the center frequencies of 3-dB bandwidths (BWs), primarily determined by their conductor lengths, range from 1.2 to 3.5 GHz.
Abstract: We discuss the design of coupled spiral transmission-line baluns modeled after the Marchand type. The balun structure consists of a pair of coupled spiral conductors vertically offset across intervening polyimide layers. The baluns are fabricated on various substrates (glass and high- and low-resistivity silicon). The characteristics such as return loss, insertion loss, and output signal imbalance are measured. The center frequencies of 3-dB bandwidths (BWs), primarily determined by their conductor lengths, range from 1.2 to 3.5 GHz. The 3-dB BW normalized by the center frequency is /spl sim/1.48 in all cases. We observe an optimum BW for better performance. Return losses at the center frequencies range from 13 to 18 dB. Amplitude imbalance distributes in the range of 0.3-1.0 dB, depending on the sizes of devices and substrates. The minimum insertion loss is 0.55 dB for the balun on a glass substrate with 100-/spl mu/m-wide conductors. The devices fabricated on glass and high resistivity (>4000 n cm) silicon show remarkably similar behaviors despite the large difference in dielectric constant. This technique is applicable to monolithic microwave integrated circuits.
89 citations
TL;DR: In this article, a Balun-bandpass filter (BPF) is proposed by using a dual-mode ring resonator, which has a bandwidth of 40 MHz and an insertion loss of 2.4 dB at a center frequency of 1.45 GHz.
Abstract: In this letter, a Balun-bandpass filter (BPF) is proposed by using a dual-mode ring resonator. The Balun-BPF is not a simply combined or integrated component of a BPF and a Balun but a single BPF with the balun function. We obtained the proper balanced outputs and two-pole BPF characteristic by symmetrically placing the output ports at lambda/2 distance from each other on the dual-mode ring resonator. The fabricated Balun-BPF has a bandwidth of 40 MHz and an insertion loss of 2.4 dB at a center frequency of 2.45 GHz. The differences between the two outputs are 180-184deg in phase and within 1dB in magnitude. The measured frequency responses agree well with simulated ones.
88 citations
TL;DR: In this article, a generalized network model for asymmetrical and inhomogeneous coupled lines has been derived based on normal mode parameters, which is useful for synthesis of single and multilayer coupled-line circuits, such as planar baluns and directional couplers.
Abstract: A generalized network model for asymmetrical and inhomogeneous coupled lines has been derived based on normal mode parameters. This model is useful for synthesis of single and multilayer coupled-line circuits, such as planar baluns and directional couplers. The synthesis procedures are described and have been verified by comparing with analysis results. >
88 citations
TL;DR: In this paper, two balun diplexers based on stub-loaded resonators are presented and carefully examined in two novel balun DIMM interfaces between a single-ended (differential) antenna and differential (single-ended) receiver.
Abstract: Two novel balun diplexers based on stub-loaded resonators are presented and carefully examined in this paper. Besides being diplexers, the two balun diplexers are also interface devices between a single-ended (differential) antenna and differential (single-ended) receiver and transmitter. The stub-loaded resonator not only has an extra degree of freedom to realize the anticipant coupling scheme, but it also can compact the circuit size and enlarge the frequency separation of the first differential- and common-mode resonant frequencies. The design procedure of the balun filter with three 50- Ω ports is introduced based on a symmetric four-port balanced-to-balanced bandpass filter. Two demonstrated balun diplexers, unbalanced-to-balanced and balanced-to-unbalanced diplexers, with Rx and Tx frequencies at 1.84 and 2.45 GHz are designed, fabricated, and measured. The implemented balun diplexers present an excellent in-band balanced performance with common-mode rejection ratio better than 38 dB over the passbands. High selectivity and isolation are also obtained by giving a cross-coupling scheme for both Rx and Tx balun filters.
88 citations
02 Jun 2002
TL;DR: In this paper, the lumped lattice-type LC-balun bridge elements are substituted by microstrip lines, which results in an improved performance at the 2nd and 3rd harmonic frequency for RF power amplifier output baluns.
Abstract: This paper presents two balun circuits derived from the lumped Lattice-type LC-balun. First the lumped LC-balun bridge elements are substituted by microstrip lines. This results in an improved performance at the 2nd and 3rd harmonic frequency for RF power amplifier output baluns. Secondly, the lumped Lattice-type LC-balun is extended to a dual band balun. Independent impedance transformation and balun conversion can be done at two different frequencies. The design equations are derived.
87 citations