Title :
A small-size adder-free π/4-shift QPSK signal generator
Author :
Yasuda, Akira ; Tanimoto, Hiroshi ; Takahashi, Chikau ; Yamaguchi, Akira ; Koizumi, Mari
Author_Institution :
Res. & Dev. Center, Toshiba Corp., Japan
Abstract :
We propose a novel adder-free architecture for realizing a small-size π/4-shift QPSK signal generator IC. In order to realize an adder function, analog current-mode addition is utilized instead of digital adders. The impulse response of a roll-off filter is stored in a ROM as a Δ-Σ modulated one-bit data stream. This can greatly reduce the die size to 0.8 mm×0.8 mm with maintaining high modulation accuracy. The test chip was fabricated by using the standard 0.8 μm CMOS technology, and the chip achieved 1.8% modulation error with a 2.7 V power supply
Keywords :
CMOS analogue integrated circuits; quadrature phase shift keying; sigma-delta modulation; signal generators; Δ-Σ modulated one-bit data stream; π/4-shift QPSK signal generator; 0.8 micron; 2.7 V; CMOS technology; adder-free architecture; analog current-mode addition; modulation accuracy; modulation error; roll-off filter; Adders; Analog integrated circuits; CMOS technology; Delta modulation; Digital integrated circuits; Filters; Quadrature phase shift keying; Read only memory; Signal generators; Testing;
Conference_Titel :
Custom Integrated Circuits Conference, 1995., Proceedings of the IEEE 1995
Conference_Location :
Santa Clara, CA
Print_ISBN :
0-7803-2584-2
DOI :
10.1109/CICC.1995.518193