Balun

About: Balun is a(n) research topic. Over the lifetime, 5375 publication(s) have been published within this topic receiving 52256 citation(s). The topic is also known as: Telephone balance unit.

Monolithic transformers for silicon RF IC design

Abstract: A comprehensive review of the electrical performance of passive transformers fabricated in silicon IC technology is presented. Two types of transformer construction are considered in detail, and the characteristics of two-port (1:1 and 1:n turns ratio) and multiport transformers (i.e., baluns) are presented from both computer simulation and experimental measurements. The effects of parasitics and imperfect coupling between transformer windings are outlined from the circuit point of view. Resonant tuning is shown to reduce the losses between input and output at the expense of operating bandwidth. A procedure for estimating the size of a monolithic transformer to meet a given specification is outlined, and circuit examples are used to illustrate the applications of the monolithic transformer in RF ICs.

RF and microwave coupled-line circuits

Abstract: Introduction. Microwave Network Theory. Characteristics of Planar Transmission Lines. Analysis of Uniformerly Coupled Lines. Broadband Forward-Wave Directional Couplers. Parallel-Coupled TEM Directional Couplers. Nonuniform Broadband TEM Directional Couplers. Tight Couplers. Coupled-Line Filter Fundamentals. Advanced Coupled-Line Filters. Filters for Advanced Materials and Technologies. Coupled-Line Circuit Components. Baluns.

Wideband Balun-LNA With Simultaneous Output Balancing, Noise-Canceling and Distortion-Canceling

Abstract: An inductorless low-noise amplifier (LNA) with active balun is proposed for multi-standard radio applications between 100 MHz and 6 GHz. It exploits a combination of a common-gate (CGH) stage and an admittance-scaled common-source (CS) stage with replica biasing to maximize balanced operation, while simultaneously canceling the noise and distortion of the CG-stage. In this way, a noise figure (NF) close to or below 3 dB can be achieved, while good linearity is possible when the CS-stage is carefully optimized. We show that a CS-stage with deep submicron transistors can have high IIP2, because the nugsldr nuds cross-term in a two-dimensional Taylor approximation of the IDS(VGS, VDS) characteristic can cancel the traditionally dominant square-law term in the IDS(VGS) relation at practical gain values. Using standard 65 nm transistors at 1.2 V supply voltage, we realize a balun-LNA with 15 dB gain, NF +20 dBm, while simultaneously achieving an IIP3 > 0 dBm. The best performance of the balun is achieved between 300 MHz to 3.5 GHz with gain and phase errors below 0.3 dB and plusmn2 degrees. The total power consumption is 21 mW, while the active area is only 0.01 mm2.

Some Broad-Band Transformers

Abstract: Several transmission line transformers are described which have bandwidth ratios as high as 20,000:1 in the frequency range of a few tens of kilocycles to over a thousand megacycles. Experimental data are presented on both transformers and hybrid circuits. Typical applications are: interstage transformers for broad-band amplifiers; baluns for driving balanced antennas and broad-band oscilloscopes; and hybrids for use in pulse reflectometers, balanced modulators, etc. These transformers can be made quite small. Excellent transformers have been made using ferrite toroids having an outside diameter of 0.080 inch.

A 1.9-GHz, 1-W CMOS class-E power amplifier for wireless communications

Abstract: This paper presents a 1-W, class-E power amplifier that is implemented in a 0.35-/spl mu/m CMOS technology and suitable for operations up to 2 GHz. The concept of mode locking is used in the design, in which the amplifier acts as an oscillator whose output is forced to run at the input frequency. A compact off-chip microstrip balun is also proposed for output differential-to-single-ended conversion. At 2-V supply and at 1.98 GHz, the power amplifier achieves 48% power-added efficiency (41% combined with the balun).