direct analog synthesis

i have heard about DDS (direct digital synthesis), but what about DAS? something opposite using analog method for PLL/synthesizer.

http://www.analog.com/Analog_Root/si...5252D1,00.html

Hi, all. Direct analog frequency synthesis refer to the method of frequency generation using mixing, frequency multiplication and abundent of filtering to generate the desired output. The base frequency is usally a stable oscillator with good phase noise. DAS yield good switching speed and phase noise, with good spurious performance. The is an old book "Frequency Synthesizer Design" ( I can remember exactly) published by John Wiley. It has detailed discussion on DAS. Alternatively, you can visit trak microwave website for some info.

PLLs are referred to as a indirect method of frequency generation.

Frequency Synthesizers by Vadim Manassewitsch

Very old , but very useful.
All kind of synthesizers , in general and in details, with problems ( like textbook) . Difficult to find in internet , this book is ~30 years old.
I have my own but unfortunally on russian, i can scan DAS chapters for pictures if you want.

try amazon , prices starts from S54.
http://www.amazon.com/exec/obidos/AS...560899-5852923