A fractional-N PLL modulator with flexible direct digital phase modulation

A 2.6 GHz fractional-N synthesizer with a flexible digital modulation scheme is presented. The PLL output is modulated by adding a digital signal directly to the output of the phase detector, in contrast to the typical method of changing the divider ratio. A pre-emphasis filter is used to allow swit...

Full description

Saved in:
Bibliographic Details
Main Authors: Ferriss, M., Lin, D.T., Flynn, M.P.
Format: Conference Proceeding
Language:English
Subjects:
Bandwidth
Detectors
Digital modulation
Filters
Phase detection
Phase locked loops
Phase modulation
Prototypes
Synthesizers
Transmitters
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A 2.6 GHz fractional-N synthesizer with a flexible digital modulation scheme is presented. The PLL output is modulated by adding a digital signal directly to the output of the phase detector, in contrast to the typical method of changing the divider ratio. A pre-emphasis filter is used to allow switching rates faster than the loop bandwidth. The transmitter supports GMSK, OQPSK, BSK or any constant envelop modulation scheme. Measurements are presented at 300 kBit/sec. The 0.7 mm 2 prototype in 0.13 mum CMOS consumes 20 mA from a 1.5 V supply.
ISSN:0886-5930
2152-3630
DOI:10.1109/CICC.2009.5280923