A 6 W MMIC Power Amplifier for 6 GHz Operation

GaAsTEK, a unit of ITT Industries
Roanoke, VA

The current trend for microwave power amplifiers is higher power and efficiency without sacrificing good linear gain. Today’s circuit designer must satisfy these requirements while also meeting stringent size and cost criteria. These somewhat conflicting goals have placed the burden squarely on device manufacturers to improve the performance of their products.

The model ITT8404 FN/FP MMIC power amplifier is a direct result of these efforts to provide the circuit designer with better components and make his or her job easier. This new MMIC amplifier provides a nominal 6 W of output power at saturation over a frequency range of 5.5 to 7 GHz and features a high linear gain of 16 dB (typ). The device is a two-stage MMIC power amplifier fabricated using the company’s mature GaAs self-aligned MSAG“ MESFET process.

This new power amplifier provides a typical power-added efficiency of 30 percent with 4 W of power output at the 1 dB compression point (P1dB). In addition, the amplifier features good linearity performance with third-order intercept points of 44.5 and 41.7 dBm at 5.5 and 7 GHz, respectively. Harmonics are typically –35 dBc at 6.25 GHz and 21 dBm input power, and spurious (nonharmonic-related outputs) are less than –45 dBc. Figure 1 shows the device’s performance with respect to input power level at 6 GHz. Figures 2 and 3 show the MMIC amplifier’s power output vs. frequency at P1dB and saturation, respectively.





The two-stage amplifier is internally matched to 50 W impedance at the input and output, making it easy to incorporate into circuit applications as well as saving PCB space and eliminating the need for additional matching components. The device is available in a high performance, ceramic flange-mount package with two pin configurations, as shown in Figure 4 . The flange-mount package has a copper-tungsten base that provides good thermal performance.

Applications for this new power amplifier include point-to-point radios where the broadband design makes the device suitable for multiple applications, and high power C-band applications such as in very small aperture terminals. The MMIC power amplifier is particularly suitable for high power applications that would normally require power FETs. Due to its internal 50 W matched input and output, the device allows a designer to use multiple MMIC stages in place of power FETs. Additional information may be obtained from the company’s Web site at www.gaastek.com.

GaAsTEK, a unit of ITT Industries,
Roanoke, VA
(540) 563-3949.