Mitsubishi
introduced an ultra-small gallium arsenide hetero-junction bipolar transistor
(HBT) that is 35 percent smaller than today's power amplifier modules
for W-CDMA(1) applications. Housed in a 6- x 5- x 1.5-mm package, the
super small BA01212 power amplifier was developed in response to the
constant demand to drive down the size and weight of mobile phones.
Picture
above shows actual device and size.
With
increasing functionality demanded from today's mobile phones for e-mail,
packet communication and Internet access, as well as demands for longer
talk-time performance, module power efficiency is a critical factor.
To achieve this, Mitsubishi Electric developed a new transistor structure
to optimize the transistor size and module circuit configuration. With
this new transistor structure, the BA01212 is able to achieve a low
operating voltage of 3.5 volts (V) and a low idle current of 50 milliamps
(mA).
"The
fashionable mobile phone and device user is constantly demanding smaller
handsets," said Bryon Gutow, senior product marketing manager for
microwave and radio frequency products at Mitsubishi Electric &
Electronics USA, Inc. "The BA01212 allows that trend to continue.
Low idle current performance at low radio frequency output operation
is key to the W-CDMA system. We have optimized low idle current at 50
mA, realizing a 42 percent high efficiency rate and in turn extending
talk-time performance."
In addition to the ultra-small package size, the GaAs HBT technology
also eliminates the need for additional peripheral circuitry, further
reducing size and space requirements. The BA01212 requires only a positive
voltage, thereby making negative voltage generation circuits unnecessary.
Similarly, integrating internal matching circuits that optimize distortion
performance eliminates the need for external matching circuits.
Packaging, Availability, and Pricing
The BA01212 GaAs HBT is housed in a 6- x 6- x 1.5-mm LTCC(2) substrate package with a metal cap. The device is available now in volume production, priced at $8.60 each in sample quantities.
Key Features
-- Frequency: 1920-1980 MHz
-- Operating Voltage: Vcc = 3.5 V, Vref = 2.9 V
-- Idle Current: Icqt = 50 mA (typical) with no RF input signal
-- Operating current: Ict = 300 mA (typical) at Po = 26.5 dBm
-- Efficiency: 42% (typical) at Po = 26.5 dBm
-- RF Performance:
-- Power Gain - Gp = 26.5 dB (typical)
-- Adjacent channel power - ACLR5 = -37 dBc (max) at +/-5 MHz
-- Adjacent channel power - ACLR10 = -48 dBc (max) at +/-10
MHz
-- RX Noise power = -144 dBm/Hz (typical)
