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.)
Mixers And More
In addition to this and other broadband amplifiers, Custom MMIC displayed its model CMD178C3 general-purpose, double-balanced fundamental mixer. Designed for upconversion and downconversion from 11 to 21 GHz, the mixer provides 6-dB typical conversion loss with a wide intermediate-frequency (IF) bandwidth of DC to 6 GHz. It has low local-oscillator (LO) leakage at the RF and IF ports (-25 and -3 dBm, respectively), and can operate with LO drive levels as low as +9 dBm.
At IMS 2013, MITEQ displayed a number of different amplifiers, including its SAFSW Series of K-band waveguide amplifiers with low noise figures (Fig. 2). Developed for use in demanding airborne applications, these amplifiers can achieve noise figures of 1.25 dB at +25°C from 18 to 21 GHz. They are designed to run on supplies of either +12 to +15 VDC or as low as +5 VDC for minimum power dissipation. An integral transmit-band filter helps minimize transmit interference signals by at least 60-dB rejection at 30 GHz.
2. This K-band waveguide amplifier was designed for demanding airborne applications. (Photo courtesy of MITEQ.)
Also at IMS 2013, oscillator house Vectron International unveiled its model HT-MM900A MEMS oscillator for clock and timing requirements over military temperature ranges. Available at frequencies from 1 to 110 MHz, the MEMS oscillator maintains ±25 ppm temperature stability from -55 to +125°C and can be supplied in packages as small as 2.5 x 2.0 mm. According to Greg Smolka, Vice President for Sales, “Our customers have reacted very positively to Vectron’s commercial MEMS product release earlier this year. However, our military customers were also interested in these same features and benefits for their designs. We’re pleased to be able to extend the capability of our MEMS portfolio with this product release.” The rugged oscillators are designed to withstand shock levels to 50,000 g and vibration to 70 g’s, with low g sensitivity of 0.1 ppb/g vibration sensitivity.
The firm will also show its extended holdover crystal oscillator (EHXO) line, including its model MX-042 (Fig. 3), designed to provide rubidium-reference frequency accuracy at a crystal oscillator price. The MX-042, designed for use in cellular base stations, enables high timing accuracy even when the master timing is lost for a cellular system. The MX-042 crystal oscillators measure just 2 x 2 x 1 in., with aging rate of just 0.06 ppb/day and low phase noise for 10-MHz outputs.
3. Model MX-042 is an extended-holdover crystal oscillator (EHXO) designed to maintain timing in cellular communications systems, even when the master clock signal is lost. (Photo courtesy of Vectron International.)
For IMS visitors seeking low-cost test equipment, Vaunix Technology Corp. showed off its Lab Brick line of compact instruments powered and connected by Universal Serial Bus (USB). By connecting to the USB port of a laptop or personal computer (PC), these compact instruments can generate and process test signals at frequencies through 20 GHz. The LMS Series of signal generators, for example, includes models for 70 to 450 MHz, 600 to 3200 MHz, and 1000 to 4000 MHz. Lab Brick phase shifters provide 1-deg. phase resolution with high accuracy, and the firm’s line of digital attenuators can now handle input levels to +33 dBm (2 W) power. The Lab Brick instruments are typically less than 1 lb. in weight and can run on battery power when a USB line is not available.
Lastly, for those in need of high-frequency interconnections, San-tron offered a variety of innovative RF/microwave coaxial connectors and cable assemblies at IMS 2013. New products included the SRX™ cable assemblies for commercial applications through 6 GHz requiring low passive intermodulation (PIM) distortion, as well as for military/avionics environments through 20 GHz. The firm also showed its eSeries connectors and cable assemblies in many popular configurations, including eSMA, Type-N, 7/16, and TNC weatherproof 50-Ω connector styles.
Editor's Note: For more show coverage, be sure to visit Microwaves & RF's IMS 2013 page.