A GaAs monolithic linear-in-dB wide-dynamic-range variable-gain amplifier with matching compensation for 1.95-GHz applications
✍ Scribed by M. Detratti; J. P. Pascual; M. L. de la Fuente; J. Cabo; J. L. García
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 574 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0895-2477
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✦ Synopsis
Abstract
This paper describes a method to design a compact linear‐in‐dB variable‐gain amplifier (VGA) with good input/output matching in a wide gain‐control range. The method is theoretically supported and has been validated with the design of a 1.95‐GHz GaAs fully monolithic VGA. Measured maximum gain is 18.8 dB with associated noise figure of 6.3 dB and 40‐dB dynamic range with lower than ±1.5‐dB deviation from linearity, under a low control voltage from −0.4 V to −1.5 V. Good linearity with an output 1‐dB compression of 12 dBm at maximum gain and associated 3^rd^‐order intercept point better than 22 dBm are also shown. The adjacent channel power ratio (ACPR) was measured at the 1.95‐GHz WCDMA band, showing values better than −48 dBc at 885‐KHz offset and −70 dBc at 1.98‐Mhz offset over the whole control range. The chip size is 2 × 1.0 mm^2^ and consumes only 34 mA from a supply voltage of 3.5 V. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 251–257, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20602