Manufacturers in the RF/microwave industry are a resilient bunch, as the attendance and activity at the recent 2013 International Microwave Symposium (IMS) in Seattle, WA will attest. The show floor was vibrant, with booth personnel radiating hope both for business to come and the new products they were unveiling. For IMS 2013 attendees the industry appeared to be alive and well, serving needs in markets that include commercial, industrial, military, and medical applications.

For example, Empower RF Systems offered fascinating live demonstrations of its high-power amplifiers at the event, using a “Size Matters” slogan to emphasize the outstanding performance of the units. The firm’s model 2162 amplifier, for example, is housed in a 5U rack-mount air-cooled enclosure and delivers more than 1 kW output power from 20 to 1000 MHz; two other models offer that much output power from 20 to 500 MHz and 500 to 1000 MHz. These power levels and frequencies are claimed for housing sizes that are considerably smaller than any other 1-kW amplifiers in the industry. The amplifiers include TCP/IP or UDP protocol sockets to form a machine-to-machine (M2M) interface with an external computer.

KCB Solutions displayed examples of its silicon, gallium arsenide (GaAs), and gallium nitride (GaN) devices, including single- and multiple-chip designs leveraging thermally enhanced materials—among them low-temperature-cofired-ceramic (LTCC) and high-temperature-cofired-ceramic (HTCC) circuit materials. The firm showed numerous high-frequency switches, including single-pole, single-through (SPST) through single-pole, six-throw (SP6T) components for high-power capabilities of 50 to 200 W. The switches are available in standard QFN housings as well as in thermally conductive flange-mount packages.

In fact, the 2013 IMS was an excellent location for anyone in need of high-frequency active devices. Cree displayed samples of its extensive GaN high-electron-mobility-transistor (HEMT) devices widely used in amplifiers for cellular communications networks, including in Long-Term-Evolution (LTE) networks. At the IMS 2013, the company announced that it had so far shipped more than two million GaN HEMT devices for wireless use.

Device supplier ANADIGICS, Inc. showed a new approach to integrated-circuit (IC) amplification with its model ASC7517, promising to provide the difficult combination of high linearity and high efficiency. The ASC7517 is designed for use from 2100 to 2170 MHz with 1.4-W output power while running on voltages of +2.85 and +5.00 VDC and power efficiency of 28%. The multistage power amplifier, which offers 42-dB gain, eliminates the need for a driver-amplifier stage. It can be used in a predistortion system to achieve demanding adjacent-channel-level-rejection (ACLR) requirements without compromising efficiency.

The device features a Doherty amplifier architecture but does not require the usual negative voltage supply, nor does it require voltage-supply optimization for achieving good performance over a wide temperature range (-40 to +85°C). It is supplied in a compact 8 x 14 x 1.3 mm surface-mount package that helps save printed-circuit-board (PCB) space.

Relative newcomer Custom MMIC introduced several GaAs monolithic microwave integrated circuits (MMICs) at its IMS booth, helping to simplify the task of circuit designers by creating GaAs MMIC amplifiers powered without need of negative bias voltages—e.g., running only on positive bias voltages. Of this “positive-bias collection,” model CMD187 is a wideband GaAs MMIC amplifier die for applications from 2 to 20 GHz (Fig. 1). It provides more than 22-dB gain through 20 GHz with 1-dB compression point of +14 dBm and noise figure of 4.5 dB at 20 GHz.

1. This wideband GaAs MMIC amplifier die is usable from 2 to 20 GHz with more than 22-dB gain through 20 GHz and noise figure of only 4.5 dB at 20 GHz. (Photo courtesy of Custom MMIC.)