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.

Planar microstrip balun

Abstract: A planar balun including first and second spaced parallel elongated conductors on one surface of a ceramic, plastic, polymer, synthetic fiber or a composite substrate and a third elongated conductor on a second surface of the substrate opposite from the first and second conductors. The spacing from an outer edge of each of the first and second conductors to an outer edge of the third conductor being greater than the thickness of the ceramic substrate, and the spacing between the two parallel elongated conductors being greater than ##EQU1## The substrate is mounted on a metallic support plate which provides a ground plane spaced from the third conductor by a distance t2 in an atmosphere comprising air with the distance t2 being greater than ##EQU2## An input of the balun is at one end of the first and second conductors and an output of the balun is at the other end of the first and second conductors. One end of the third elongated conductor on the second surface is grounded to force a balance at the two outputs.

Broad bandwidth transformer coupled differential amplifiers for high dynamic range

Abstract: Broad bandwidth amplifiers are typically limited in their spurious free dynamic range by second-order products. We have demonstrated more than 30 dB reduction in second-order products for amplifiers with 1-2 octaves of bandwidth utilizing a novel circuit approach. Improved planar baluns (180/spl deg/ transformers) are combined with differential amplifiers fabricated from 0.25-/spl mu/m GaAs pseudomorphic high electron mobility transistors to implement 4-16-GHz and 3-6-GHz small-signal amplifiers. Measured values of OIP2 exceed 60 dBm with a 1-dB compression level of approximately 5 dBm. These unprecedented levels enable miniaturized, low-power front ends for broad bandwidth microwave systems.

Method and system for a lumped-distributed balun

Abstract: Systems to provide and methods to design a printed lumped-distributed balun are presented. A lumped-distributed balun includes a single-ended port, a first differential port, a second differential port, a first phase shifter circuit, and a second phase shifter circuit. The first phase shifter circuit includes a first inductor and a first capacitor. The first inductor is coupled to the single-ended port and the first differential port. The first capacitor is coupled to the first differential port and is adapted to be coupled to ground potential. At least one of the first inductor and the first capacitor is implemented as a transmission line structure, such as microstrip. The second phase shifter circuit includes a second inductor and a second capacitor. The second inductor is coupled to the second differential port and is adapted to be coupled to ground potential. The second capacitor is coupled to the single-ended port and the second differential port. At least one of the second inductor and the second capacitor is implemented as a lumped element.

A Wide-Band Parallel-Connected Balun

Abstract: It is pointed out that parallel-connected baluns (4:1 impedance transformation) have approximately four times the operating bandwidth of series-connected baluns (1:1 impedance transformation). The simple theory of uncompensated resonant baluns is discussed, and design curves are presented which may be used to design any balun of this type. Experimental results are given on one type of parallel-connected balun showing it capable of a 25:1 operating bandwidth as predicted by theory. Operating over this bandwidth, the balun is only /spl lambda/ / 25 in length at the lower band-edge frequency. Because of its 4:1 impedance transformation, the balun should be very useful in the feeding of frequency-independent antennas with high impedance, such as the conical spiral.

Dual-frequency balun to decrease influence of RF feed cables in small antenna measurements

Abstract: A dual-frequency balun applied in connection with measurements of small dual-frequency antennas reduces parasitic currents on the surface of the RF feed cable, so that the influence of the RF measurement cable on the radiation pattern is minimised.