Analog Devices has introduced two new high-performance gallium nitride (GaN) power amplifier (PA) modules which offer one of the highest power-density levels in their class, thus minimizing size and weight of the subsystem. The HMC7885 and HMC7748 broadband modules target applications operating between 2 GHz and 6 GHz, including test and measurement, communications, Traveling Wave Tube (TWT) replacement, military/aerospace surveillance and countermeasures, and radar. The fully integrated, all solid-state devices expand ADI's existing line of GaN-based PAs, and feature ease of use to accelerate prototyping and system design.
The HMC7885 is a 32 W GaN MMIC power amplifier module that operates between 2 GHz and 6 GHz. It is available in an 18-lead hermetically sealed module. The amplifier typically provides 21 dB of small signal gain and 45 dBm of saturated radio frequency (RF) output power. The amplifier draws 2200 mA of quiescent current (IDD) from a 28 V DC supply. The RF input and output are dc blocked and matched to 50 Ω for ease of use. An evaluation board is available with layout and bill of materials to facilitate design-in and user application.
The HMC7748 is a multistage power amplifier (PA) that provides 25 W of saturated output power from 2 GHz to 6 GHz with a gain of up to 60 dB. It draws 0.7 A from a 12 V supply and up to 4 A from a 28 V supply. The 12 V supply is regulated internally and generates the negative voltage required for the gate bias. Built-in bias sequencing prevents the drain voltages for the amplifier stages from being applied without the negative voltage present, which protects the amplifiers if 28 V is applied without 12 V supply applied. An external enable pin causes the module to remain in shutdown mode unless the pin is pulled to ground. This pin provides a means of turning the amplifiers off and on without cycling the power supplies.
These GaN power amplifiers provide significant advances in performance and packaging, for broadband, medium-power applications. They can be used in Test and measurement equipment, Electronic warfare (EW) systems, communication systems, as TWT replacements and a range of other applications that required high power from an amplifier in a compact package.
