A series of high performance wideband MMIC low noise, gain block and driver amplifiers has been developed for applications in next-generation radar and satcom equipment. These new amplifiers operate in the 2 to 20 GHz frequency range and feature a single-supply, low noise and distributed gain functionality. The amplifiers have been created using M/A-COM's MSAG multi-level plating (MLP) process that utilizes multiple low dielectric constant polyimide layers and thick metallization layers atop the base GaAs. The MLP process allows for low loss, higher frequency operation and increased flexibility in the development of higher power components.

The MLP process differs from a more standard wafer processing in that it incorporates the addition of a second low dielectric constant polyimide layer and a second thick gold metallization layer. The additional polyimide layer offers the flexibility to locate transmission lines on polyimide up to 10 µm thick. This offers the ability to design using very high impedance transmission lines that are critical for high frequency distributed amplifiers. These lines can also be implemented using relatively wide transmission lines, thus resistive losses are reduced.

The additional thick metallization layer offers benefits mostly in the area of DC current routing and high power design. The designer now has the flexibility to use 9 µm thick transmission lines, which allow 20 mA/µm current handling. This permits the creation of higher current structures, such as spiral inductors for compact designs.

The New Amplifier Family

The new series of amplifiers is comprised of four basic designs: the MAAPGM0052-DIE distributed power amplifier, the MAALGM0008-DIE single-supply, low noise amplifier, the two-stage MAALGM0006-DIE low noise amplifier and the MAAMGM0007-DIE distributed amplifier/gain block. All four amplifiers offer an upgrade path from prior products as well as performance features and enhancements that allow them to be used to easily retrofit existing microwave amplifiers. Their individual features and characteristics follow.

Distributed Power Amplifier

The model MAAPGM0052-DIE is a distributed power amplifier operating from 4.5 to 19.0 GHz and delivering up to 27 dBm of output power, as shown in Figure 1. The amplifier is a two-stage device containing on-chip bias networks and is fully matched to 50 with an input and output VSWR of 1.4 and 1.5, respectively. It is best used in high power applications as a power amplifier or driver amplifier, where up to 14 dB of small-signal gain is required.

Fig. 1 MAAPGM0052-DIE saturated output power and small–signal gain vs. frequency for VD = 8 V.

Single-supply Distributed Amplifier

The model MAALGM0008-DIE is a single-stage, low noise amplifier with 10 dB of gain and a typical noise figure across the operating band of 5 dB. Its most notable features are its single-supply operation and gain flatness from 2 to 20 GHz, as shown in Figure 2. Other features include a variable (3 to 6 V) drain voltage operation and up to 20 dBm of output power. This device operates from 2 to 20 GHz with an input and output VSWR of 1.4 and 1.5, respectively.

Fig. 2 MAALGM0008-DIE small–signal gain, and input and output VSWR at VD = 5 V.

Low Noise Amplifier

For applications where noise is a key design parameter the two-stage model MAALGM0006-DIE device typically exhibits less than 3.5 dB of noise over its entire 2 to 6 GHz operating range. Like its counterparts, this amplifier is impedance matched to 50 on the input and output with VSWRs of better than 1.5. Optimally designed for the most demanding radar, satcom and point-to-point radio applications, its variable drain voltage operation (4 to 10 V) allows for flexibility in its end use. Key characteristics include a small-signal gain of 17 dB, low DC power consumption and 50 mW of saturated output power.

Distributed Amplifier/Gain Block

The model MAAMGM0007-DIE is a single-stage, distributed amplifier with a single-supply operation specified at +8 V for applications that require a cascadable gain block and 22 to 23 dBm of output power over a 2 to 18 GHz frequency range. The device delivers 9 dB of small-signal gain and typically has a VSWR better than 2.0, as shown in Figure 3. Its variable drain voltage (5 to 8 V) allows for flexibility in its end use while maintaining the displayed RF performance. In addition to radar and electronic warfare, test equipment is among its primary target applications.

Fig. 3 MAAMGM0007-DIE small–signal gain, VSWR and output power at VD = 5 V.

All of the amplifiers are manufactured using M/A-COM's high yield MSAG® (Multi-function Self-aligned Gate) MESFET GaAs process using selective ion implantation to integrate microwave and digital FETs in a single MMIC with extremely high yield, repeatable electrical characteristics and low parasitics. Each device is 100 percent RF tested on wafer to ensure performance compliance.

Pricing for 1000-piece quantities is:
MAAPGM0052-DIE $58.40
MAALGM0008-DIE $37.01
MAALGM0006-DIE $28.43
MAAMGM0007-DIE $34.05

All models are available from stock. Individual data sheets and supporting information are available from the company's Web site at www.macom.com.

M/A-COM Inc.,
Lowell, MA
(800) 366-2266.
Circle No. 302