HMMC-5203 23 GHz LNA (21.2–26.5 GHz)

Description

The HMMC-5023 MMIC is a highgain low-noise amplifier (LNA) that operates from 21 GHz to over 30 GHz. By eliminating the complex tuning and assembly processes typically required by hybrid (discrete–FET) amplifiers, the HMMC-5023 is a cost effective alternative in both 21.2-23.6 GHz and 24.5-26.5 GHz communications receivers. The device has good input and output match to 50 ohms and is unconditionally stable to more than 40 GHz. The backside of the chip is both RF and DC ground. This helps simplify the assembly process and reduces assembly related performance variations and costs. It is fabricated using PHEMT integrated circuit structure that provides exceptional noise and gain performance. 

Applications

The HMMC-5023 low noise amplifier (LNA) is designed for use in digital radio communication systems that operate within the 21.2 to 23.6 GHz and 24.5 to 26.5 GHz frequency bands. High gain and low noise temperature make it ideally suited as a front-end gain stage. The MMIC solution is a cost effective alternative to hybrid assemblies.

Biasing and Operation

The HMMC-5023 has four cascaded gain stages as shown Figure 1. The first two gain stages at the input are biased with the VD1 drain supply. Similarly the two output stages are biased with the VD2 supply. Standard LNA operation is with a single positive DC drain supply voltage (VD1 = VD2 = 5 V) using the assembly diagram shown in Figure 8(a).

If desired, the output stage DC supply voltage (VD2) can be increased to improve output power capability while maintaining optimum low noise bias conditions for the input section. The output power may also be adjusted by applying a positive voltage at VG2 to alter the operating bias point for both output FETs. Increasing the voltage applied to VG2 (more positively) results in a more negative gate-to-source voltage and, therefore, lower drain current. Figures 8(b) and 8(c) illustrate how the device can be assembled for both independent drain supply operation and for output-stage gate bias control.

No ground wires are required since ground connections are made with plated through-holes to the backside of the device.

Assembly Techniques

It is recommended that the RF input and RF output connections be made using either 500 line/inch (or equivalent) gold wire mesh, or dual 0.7 mil diameter gold wire. The RF wires should be kept as short as possible to minimize inductance. The bias supply wire can be a 0.7 mil diameter gold wire attached to either of the VDD bonding pads.

GaAs MMICs are ESD sensitive. ESD preventive measures must be employed in all aspects of storage, handling, and assembly. MMIC ESD precautions, handling considerations, die attach and bonding methods are critical factors in successful GaAs MMIC performance and reliability. Keysight Technologies, Inc. application note (5991-3484EN), “GaAs MMIC ESD, Die Attach and Bonding Guidelines” provides basic information on these subjects.