MMIC amps make a small noise for Ommic
by Andy Extance in Atlanta
Ommic looks set to enhance its strong presence in cellular base stations with the release of what it claims are the highest performance low-noise amplifiers on the market.
The French GaAs chipmaker was promoting one MMIC amplifier aimed at 1.9 GHz transmission and another aimed at 0.9 GHz during the International Microwave Symposium in Atlanta, Georgia, from June 17-19.
“They have a combination of extremely low noise and extremely high linearity,” Marc Rocchi, Ommic s CEO, told compoundsemiconductor.net. He explained that the low noise figure enables a base station to deal with a large number of simultaneous calls, while increased linearity extends its range.
Both low-noise amplifiers (LNAs) are fabricated using Ommic s 0.13 µm GaAs PHEMT process. The 0.9 GHz LNA boasts a 0.44 dB noise figure when producing 19 dB of gain at 36.5 dBm output IP3. When the 1.9 GHz LNA also delivers 19 dB gain with an output IP3 of 35 dBm its noise figure is 0.42 dB.
The PHEMT process allows Ommic to combine an attenuator, phase shifter, power amplifier, switch and the overall device s digital control onto a single GaAs chip.
The analog functions are performed by depletion-mode PHEMT functionality, while digital functions are performed by enhancement-mode PHEMT architecture. These LNAs are currently available in sample volumes, targeting wireless infrastructure and base station markets across a range of transmission standards.
Approximately half of all GSM cellular base stations currently contain Ommic s LNAs and other devices, it claims. This momentum was gained while Ommic was a subsidiary of electronics giant Philips, from which it spun out last year via a buy-out that its management was intimately involved in (see related story). “We have a very large part of the base station business,” Rocchi asserted.
Outside of base stations the company is also producing increasing volumes of chips that use its GaAs digital control PHEMTs, in areas including phased array radar and antennas for space applications.
Andy Extance is a reporter for compoundsemiconductor.net.