Wideband amplifier modules find uses in a variety of industries, including in communications and test applications. A new line of hybrid power amplifier modules (HPMs) from AR RF/Microwave Instrumentation provides coverage from 6 to 18 GHz with a wide range of choices in signal gain and output power, including two models with noise figures as low as 3 dB. The simple-to-integrate modules are cascadable 50-Ohm system building blocks designed to operate on a single DC supply voltage with low distortion and flat gain.
The company leverages new in-house capabilities of its microelectronics manufacturing facility to produce the compact and reliable HPMs (Fig. 1). Assembly techniques are geared toward the use of bare transistor die and monolithic-microwave-integrated-circuit (MMIC) devices as well as passive devices in die form. Based in Souderton, PA, the microelectronics manufacturing facility is housed in a clean-room environment that adheres to strict electrostatic-discharge (ESD) requirements. Manufacturing capabilities include eutectic and epoxy die attach, automatic and manual wedge/ball wire bonding, ribbon bonding, and parallel gap welding.
The broadband hybrid amplifiers employ plated-through-hole (PTH) technology for reliable interconnections between circuit layers, as well as proven air-bridge technology for low-loss connections between active devices and circuit traces. The HPMs, which are designed for mounting on external heat sinks, borrow sound thermal practices from the company's larger (and lowerfrequency) EMI/EMC power amplifiers. The rugged hybrid amplifiers are hermetically sealed and constructed to meet the demands of military applications but fit within the cost constraints of most broadband commercial applications, including communications systems and test equipment. All of the new HPMs are supplied with field-replaceable RF input and output (SMA female) connectors.
The HPMs feature excellent input and output return-loss performance as evidenced by low input/output VSWR performance of 2.0:1. The good input and output match ensures stable and repeatable performance when multiple amplifiers are cascaded or combined with other components in a signal-processing chain. In addition, the amplifiers are extremely tolerant of a wide range of load conditions for stable, oscillationfree performance.
Six HPMs have been developed for applications from 6 to 18 GHz, with more to follow (see table). They offer rated output power levels from +24 to +37 dBm with minimum gain of about 10 to 34 dB and noise figures of 3 or 6 dB. All of the amplifiers are designed for worst-case gain flatness of 2 dB from 6 to 18 GHz with typical gain flatness of 1 dB. They produce low spurious content with excellent linearity, making them well suited for boosting the levels of modulated signals. For example, model 24HM6G18-24 yields +23 dBm minimum output power and +24.5 dBm nominal output power from 6 to 18 GHz. Under more saturated conditions (3-dB compression, it provides +24 dBm minimum output power and +26 dBm nominal output power. The compact module, which measures 1.24 x 2.10 x 0.3 in., delivers 22 dB minimum gain with 3 dB typical noise figure. It has a typical third-order intercept point of +34 dBm and draws 420 mA from a single +10-VDC supply. The amplifier has harmonic distortion of -20 dBc when generating +23 dBm output power. It features 100 percent mismatch tolerance at its rated output power without foldback, operating without damage or oscillation with any magnitude or phase of the source or load impedance. The HPM is designed to faithfully reproduce signals with amplitude modulation (AM), frequency modulation (FM), and pulse modulation.
With somewhat higher power, model 29HM6G18-34 provides +28 dBm minimum output power at 1-dB compression from 6 to 18 GHz, with +29 dBm minimum output power at 3-dB compression and a typical third-order intercept point of +37 dBm. It achieves 33 dB minimum gain with 3 dB typical noise figure while consuming 1200 mA current from a single +10-VDC supply. Harmonics are -20 dBc for a +28 dBm output level.
Model 32HM6G18-10 delivers +31.5 dBm minimum and +32 dBm nominal output power at 1-dB compression, with +32 dBm minimum and +33 dBm nominal output power at 3-dB compression. The minimum gain is 9 dB, with a typical noise figure of 6 dB. The gain flatness is typically 1 dB across the full frequency range. The module, which measures 1.24 x 2.10 x 0.3 in., achieves typical thirdorder intercept point of +40 dBm and draws 1800 mA current from a single +10-VDC supply. Harmonic distortion is rated at -20 dBc for an output level of +32 dBm.
Model 32HM6G18-17 offers +31.5 dBm minimum and +32 dBm nominal output power at 1-dB compression, with +32 dBm minimum and +33 dBm nominal output power at 3-dB compression. It provides minimum gain of 15 dB with typical noise figure of 6 dB. Measuring just 1.24 x 2.72 x 0.3 in., the HPM achieves a typical third-order intercept point of +40 dBm. Harmonic distortion is limited to -20 dBc for an output-power level of +32 dBm.
Model 35HM6G18-22 generates +34 dBm minimum and +35 dBm nominal output power at 1-dB compression, with minimum output power of +35 dBm and nominal output power of +36 dBm at 3-dB compression. The minimum gain is 21 dB, with typical noise figure of 6 dB. The HPM measures 1.97 x 3.25 x 0.3 in. and achieves a third-order intercept point of typically +44 dBm. The amplifier module draws 4.4 A from a single +10-VDC supply and exhibits harmonic distortion of -20 dBc for an output-power level of +35 dBm.
The model 37HM6G18-10 HPM offers the lowest gain but the highest output power at 1-dB compression, with 10 dB and +37 dBm, respectively. In order to support the higher output-power level, it is the largest of the standard HPM models, at 4.24 x 5.80 x 0.3 in. With a third-order intercept point of +46 dBm, this is an amplifier module ideal for applications requiring widedynamic- range amplification. It sports a relatively low noise figure of 6 dB and limits harmonic distortion to -20 dBc for an output level of +35 dBm. It draws 7 A from a +10-VDC supply.
In addition to the standard models, the company's in-house design and manufacturing facilities make custom HPM design solutions from DC to 20 GHz and higher. The amplifier modules can be designed according to specific size and weight requirements. AR RF/ Microwave Instrumentation, 160 School House Rd., Souderton, PA 18964-9990; (800) 933-8181, FAX: (866) 859-0582, E-mail: [email protected]. Internet: www.ar-worldwide.com.