A 10-bit wide-band CMOS direct digital RF amplitude modulator
Author
Summary, in English
This paper describes a low-distortion wide-band CMOS direct digital RF amplitude modulator, which uses a 10-bit linear interpolation current-steering digital-to-analog converter (DAC) and a Gilbert-cell-based mixer to generate an amplitude modulated RF signal directly. The linear interpolation increases the attenuation of the DAC's image components. The reconstruction filter is, therefore, eliminated. The DAC's differential current signals are directly sent to the mixer, which improves the linearity of the modulated RF signal. Thus, the RF transmitter structure is simplified, and the low distortion is achieved. This modulator is suitable for system-on-chip (SOC) design and is easily scalable. The chip was fabricated in a 0.35-/spl mu/m 3.3-V double-poly triple-metal CMOS process. The core size of the chip is 0.52 mm/spl times/0.68 mm. With a 3.3-MHz modulation signal, a 50-MHz clock, and a 1-GHz carrier, the distortion components are below -53.81 dBc, and the attenuation of the image signal is 47.45 dB. The output power is -6.5 dBm, and the total power consumption is 159.8 mW.
Publishing year
2003
Language
English
Pages
1182-1188
Publication/Series
IEEE Journal of Solid-State Circuits
Volume
38
Issue
7
Document type
Journal article
Publisher
IEEE - Institute of Electrical and Electronics Engineers Inc.
Topic
- Electrical Engineering, Electronic Engineering, Information Engineering
Keywords
- radio-frequency integrated circuit
- CMOS integrated circuit
- amplitude modulation
- digital-to-analog
- converter (DAC)
- (RFIC)
- interpolation
Status
Published
ISBN/ISSN/Other
- ISSN: 0018-9200