News Release

- New Product Information -

A shrunken Digital transceiver; AKM releases a Cartesian Feedback Loop transmission IC with DAC and PLL

Product Name
Product Category:
Two way Radio ICs
Cartesian Feedback Loop Transceiver IC for Narrow Band Radio Communication
Professional Digital Mobile Radios
Narrow Band Radio Communication:
6.25kHz / 7.5kHz / 12.5kHz / 15kHz / 20kHz / 25kHz / 50kHz / 100kHz / 150kHz / etc.
Modulation Method:
π/4DQPSK / QPSK / 16QAM / 64QAM / etc.


Asahi Kasei Microdevices Corporation, (AKM), has started mass production of the AK2403, a narrow band radio transceiver IC.  The AK2403 achieves high linearity which is required for the QPSK and QAM modulation methods using Cartesian Feedback Loop technology.  Since the AK2403 integrates a DAC and PLL circuits, it contributes to size reduction of the transmission block in professional digital mobile radios.
In addition, AKM has started mass production of the AK2401A (*), a new direct conversion transmitting/receiving IC.  It uses a simple PSK radio system that was normally composed from many discrete parts with a combination of a transmission IC, the AK2403.

∗ The AK2401A reduces power consumption current by 10% at the receiving block, (not including PLL, in Low Power Mode), and increases blocking resistance characteristics by 3dB, (with an external demodulator, measured according to the TIA-603 standard), by comparing with the AK2401.


● Integrated D/A Converter and PLL

Digital signals from a digital baseband IC can be directly received since the AK2403 integrates DACs.  The output range of the DAC can be adjusted by 1dB steps with a range from -8dB to 7dB and it can be adjusted by 0.1dB step from 0dB to 1.5dB.
The internal PLL covers LO frequency from 50MHz to 1.0GHz with a Fractional-N synthesizer.  An internal or an external VCO can be used with the internal PLL.  Low phase noise can be realized with the internal VCO.

● Easily achieved DC offset calibration

The AK2403 has a DC offset calibration function that detects the DC offset from the full differential amplifier output and cancels it.  DC offset calibration can be executed easily just by writing “1” to the register setting.

● Great Wideband Noise (WBN) Characteristics

The AK2403 achieves -105dBc WBN characteristics with enough margins to cover the most difficult standard value of -100dBc, which is TETRA standard’s WBN with 5MHz offset.  (Measurement Conditions: 400MHz Frequency, 3W Output)

Main Specifications

Cartesian Feedback Loop Transceiver IC for Narrow Band Radio Communication
Operating Frequency50 to 1000MHz
Forward Path
(Differential Amplifier, Quadrature Modulator)
Gain: 31dB (1dB step)
Feedback Path
(Attenuator, Quadrature Demodulator,Differential/Single-ended conversion amplifier, Phase Shifter)
Attenuator Gain: 31dB (1dB step)
360-degree phase shifting (in 5.625-degree step)
Differential/Single-ended Conversion Amplifier: 11dB (1dB step)
12-bit DACMaximum Sampling Frequency: 1MHz
Gain Coarse adjustment: 15dB (1dB step)
            Fine adjustment: 1.5dB (0.1dB step)
ΔΣ Fractional-N PLLCorrespond to Internal VCO Mode, External VCO Mode, and External LO Input Mode
FunctionsOut of Band Instability Detector
DC Offset Calibration
Local Signal Dividing CircuitDivide by 2, 4, 8, 16
TCXO Frequency10 to 40MHz
Package68-pin QFN  (8 × 8 × 0.85mm, 0.4 mm pitch)
* Information on this page is current on the date of press release.
* AKM is a trademark of Asahi Kasei Microdevices Corporation in Japan, Europe and the United States.
* Appellations, company names and product names on this page are trademarks or registered trademarks of respective companies.

Page Top