CXG1178K |
| . |
. |
|
* High efficiency,
low distortion
* Low Rx band noise
* Single positive power supply operation
* Miniature package
* Built-in temperature compensation circuit |
|
 |
| |
|
Miniature
Package, High Efficiency, and Low Distortion |
|
Sony has developed
a new low on-resistance miniature JPHEMT* device
to achieve higher performance and further miniaturization
of the IC chip. Based on the low-loss matching
circuit technologies Sony has cultivated up
to now, Sony has also made the module matching
circuits even more compact by reducing the number
of components and using even smaller components.
The result has been the creation of a miniature
power amplifier module with an area, 4.5 mm
square, that is about 1/2 that of earlier Sony
power amplifier modules. Since CDMA uses output
power control during transmission, distortion
and efficiency are important not only in high
output power mode, but in low-voltage low output
power mode as well. The JPHEMT device developed
by Sony exhibits superlative low distortion
and high efficiency characteristics not only
in high output mode but in low-voltage low output
power mode as well. Taking advantage of these
characteristics, the CXG1178K achieves, in high
output power mode, an operating voltage of 3.5
V, an output power of 27.5 dBm, an ACPR1 of
-52 dBc, and an efficiency of 40.5%. In low-voltage
low output power mode, the CXG1178K achieves
an efficiency of 17.6% at an operating voltage
of 1.5 V and an output power of 14 dBm, and
at an operating voltage of 1.5 V and an output
power of 18 dBm, it achieves an ACPR1 of -55
dBc. Thus the CXG1178K achieves the industry's
top level of device characteristics in all the
modes required by the CDMA system. (See table
1 and figure 1.) |
|
Low Rx Band
Noise |
|
Due to the excellent
low noise characteristic of JPHEMT, the CXG1178K
achieves the -140 dBm/Hz Rx band noise of the
industry's top level. |
|
Single Positive
Power Supply Operation |
|
Sony's unique JPHEMT
device has a high built-in voltage, and that
makes it possible to implement a power amplifier
module that operates on a positive power supply.
This obviates the need for peripheral circuits
such as a negative power supply generator circuit,
and contributes to further miniaturization and
lower costs in portable terminals. |
|
Miniature
Package |
|
A miniature package
with a volume of only 0.03 cc (4.5 mm x 4.5
mm x 1.35 mm) was adopted for the CXG1178K.
This contributes to reduced mounting areas and
further miniaturization in portable terminals.
(See figure 2.) |
|
Built-in Temperature
Compensation Circuit |
|
The power amplifier
bias current varies widely with changes in temperature,
and that can result in a corresponding degradation
of device characteristics. The CXG1178K includes
a built-in temperature compensation circuit
that controls the bias current to be optimal
for the temperature as the temperature changes.
This minimizes the degradation in device characteristics
at both high and low temperatures.
* JPHEMT: Junction Pseudomorphic High Electron
Mobility Transistor |
|
|
| |
|
|
|
•••• Mr.KOIMORI ••••
|
|
|
The CXG1178K was developed
with miniaturization and high performance as
the targets. We started by developing a miniature
high-performance transistor, and we then found
the optimal circuit from a large number of circuit
patterns by repeatedly evaluating actual circuits.
We are proud of this device, which was completed
due to the united efforts of the whole development
team. I hope you will be able to discover for
yourself how good this device really is. |
|
 |
See
all articles with figures and tables.  |
|
Vol.37 |
|
