News is made when a firm associated with a particular product line branches out into uncharted territory. Such is the case with longtime power-amplifier supplier CTT, Inc. (Sunnyvale, CA) that recently announced an extensive line of low-noise amplifiers (LNAs) in broadband and narrowband configurations through 20 GHz.

Suitable for both commercial and military applications, the amplifiers aim at a different part of the communications system block diagram than the company's traditional lines of power amplifiers targeting transmitters. These new LNAs, which are based on GaAs pseudomorphic high-electron-mobility-transistor (pHEMT) active devices, represent another component source for receiver designers in need of a combination of low noise, high gain, and wide dynamic range. The new M series LNAs (see figure) offer input and output impedance matching tailored to support either narrowband operation over a specific frequency range or wideband operation for octave and multi-octave operation. The amplifiers are designed for +12- to +15VDC operation.

The LNAs are available in a several packages, both with and without SMA connectors. Package sizes, for example, include the M2 housing, measuring 0.16 X 0.28 X 0.43 in., the M3 housing, at 0.16 X 0.32 X 0.53 in., the M4 housing, at 0.22 X 0.43 X 0.64 in., and the M5 package, at 0.22 X 0.53 X 0.75 in.

Examples of the firm's narrowband LNAs include the models AMN/0391010 and AMW/170-2510. Model AMN/039-1010 features 1 dB maximum noise figure from 3.1 to 3.9 GHz with 10 dB minimum gain and 0.5 dB maximum gain flatness. The minimum output power is +8 dBm. The single-stage amplifier is supplied in an M3 package. By adding a gain stage, model AMN/0391020 in an M4 housing results, with 1 dB maximum noise figure and 20 dB minimum gain 3.1 to 3.9 GHz. And model AMN/039-1030 provides 30 dB gain and 1 dB maximum noise figure from 3.1 to 3.9 GHz, also in an M4 housing.

The highest-frequency narrowband unit currently offered is model AMW/1702510, with 2.5 dB maximum noise figure and 10 dB minimum gain from 14.0 to 17.0 GHz. As with other narrowband models, amplifiers in 10-, 20-, and 30dB gain versions are available.

For those needing more wideband signal coverage while maintaining low noise figures, the firm currently offers 30 wideband LNAs with frequency ranges covering 0.5 to 2.0 GHz through 2 to 20 GHz. For the octave band model AMO/040-1816, for example, the noise figure is only 1.8 dB from 2 to 4 GHz with 16 dB gain and 1 dB maximum gain flatness. The output power at 1-dB compression is at least + 8 dBm. The amplifier draws 80 mA current from a +12- to +15-VDC supply.

The broadest bandwidth amplifier is model AMX/0220-4510 with maximum noise figure of 4.5 dB and 10-dB minimum gain from 2 to 20 GHz. The amplifier provides minimum output power of +8 dBm. Supplied in an M4 housing, it consumes 80 mA at +12 to +15 VDC. Additional broadband LNAs are available for a variety of frequency ranges, including 0.5 to 10.0 GHz, 0.5 to 18 GHz, and 6 to 18 GHz.
CTT, Inc., 241 East Java Dr., Sunnyvale, CA 94089; (408) 541-0596, FAX: (408) 541-0794, Internet: www.cttinc.com