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9 December 2008


Mitsubishi Electric launches low-noise GaAs HEMT for satellite digital radio

Tokyo-based Mitsubishi Electric Corp says that it has developed the MGF4921AM, a low-noise GaAs high-electron-mobility transistor (HEMT) suitable for low-noise amplifiers in receiver systems for satellite digital radio as well as C-band direct broadcast satellite (DBS).

Satellite digital audio radio service (SDARS), which since 2001 has become commonplace in North America, does not require tuning to adapt to regional broadcasting like analog radio services, attracting the use of SDARS in automobiles for information services such as traffic information and entertainment programs. With similar digital audio broadcasting (DAB) data services also expected to start in other regions of the world, the satellite digital radio market is expected to grow globally in the near future.

At the same time, regarding receive systems for satellite digital radios, a reception converter inside the antenna receives S band (2-4GHz) waves from satellites and converts them into a mid-frequency band of 0.8-1.5GHz to send them to the signal processing circuit. There is increasing demand for HEMTs, used in low-noise amplifiers for these converters and, to improve radio sensitivity, there is a need for low-noise HEMTs with higher performance.

Mitsubishi Electric says that it is difficult to balance stability and low-noise characteristics when using 12-20GHz low-noise GaAs HEMTs for low-frequency bands. But, by optimizing the gate width and improving stability for low frequency bands, it has improved the device noise figure to 0.35dB, which is claimed to be an industry-best and 0.1dB lower than the firm’s 12GHz model (the MGF4953A), when measured at 2.4GHz on a stable matching circuit. Using the MGF4921AM in the first stage of amplifiers (which demands low-noise characteristics) improves the sensitivity in reception converters for satellite digital radios, helping to expand the radio coverage area and to decrease production costs in reception converters, Mitsubishi Electric claims.

The MGF4921AM is housed in an industry-standard 4-lead full-mold package. An unchanged footprint pattern from the previous model should shorten development periods for satellite communication equipment makers, the firm reckons. The sample price is 30 yen. Shipment will begin on 26 January, with production at 500,000 units per month.

Mitsubishi Electric says that, for the second and third stages of amplifiers, it will add to its lineup of low-noise GaAs HEMTs with improvements in output power and distortion characteristics.

See related items:

DBS GaAs component volumes to be driven by digital video

Mitsubishi Electric installs Aixtron MOCVD reactor for blue-violet lasers

Mitsubishi Electric launches high-power InGaP HBT amplifier for WiMAX terminals

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