Since semiconductor device performance is a function of temperature, an amplifier’s small-signal gain will change as the temperature varies, decreasing as the temperature increases and increasing as the temperature decreases. This can adversely impact the performance of a system if this gain variation is not accounted for. To help designers address this variability, Fairview Microwave offers a family of temperature compensated amplifiers that operate from -55°C to +85°C and reduce gain variation by 2x to 3x compared to an uncompensated amplifier at +85°C, the gain of the compensated amplifier will be 1.0 to 1.5 dB lower than the room temperature (+25°C) gain; at -55°C, it will be 1.0 to 1.5 dB higher. Temperature compensation is accomplished by using voltage-controlled attenuators driven by thermistor circuitry, located between the amplifier’s gain stages.
Fairview’s temperature compensated portfolio comprises 12 models covering frequency ranges from 500 MHz to 40 GHz, all with minimum gains of 35 dB over the full temperature range. The 50 Ω amplifiers are assembled using MMICs and thin film circuits in housings with coaxial feeds, either SMA or 2.92 mm. As examples of the amplifiers in the family, the FMAM5101 at +25°C provides 47 dB typical gain from 500 MHz to 4 GHz, with gain flatness less than ±1.75 dB, maximum noise figure of 4.5 dB and typical P1dB of 21 dBm. For mmWave applications, the FMAM5108 provides 45 dB typical gain from 26.5 to 40 GHz, with ±3 dB flatness, less than 8.5 dB noise figure and 18 dBm typical P1dB.
Fairview’s amplifier modules provide repeatable performance and high reliability, suitable for demanding applications such as aerospace and defense, test and measurement, communication systems and general R&D.