A question about how to make a Oscillator of 1GHZ,PLS HELP~~
and i design a plan:a oscillator at 315MHZ+pll+vco,and then PLL+VCO makes the 315MHZ up to 945MHZ can it works?
any other idears? thanks~~~~~
and waht i should note in layout the PCB,?
THANKS~~~~~~~~~~~~
before the PCB u need to know ,how to design each circuit , and then go to the layout
ur VCO range is very high
u need alot of work
Khouly
How about a crystal oscillator @ 13 MHz, so you can use a cheap GSM reference crystal, then a VCO @ 945 MHz, and a PLL. Pick the divide ratio's to give you the right channel spacing.
An excellent PLL reference is here
webench.national.com/appinfo/wireless/pll_designbook.html
and you can use National Semiconductor's Easy PLL part selector at
webench.national.com/appinfo/webench/EasyPLL/easypll.cgi?flow=wireless&step=1A
For a 900 MHz VCO, I'd be tempted to look at a packaged VCO module to make this easier.
Dave
www.keystoneradio.com
If I were a student and wanted to get the most bang out of project like that, I would make:
1) A 315 MHz PLL
2) A X3 frequency multiplier to get up to 945 MHz
3) An output bandpass filter and amplifier to clean the desired output up.
You could just use a 1 gbit type digital gate to do the X3, as the square wave output would be rich in 3rd harmonics. Something like a 74LVC1G17DBVR gate.
Alternatively you could make a diode or fet frequency multiplier.
Such a project would look great on your resume. You would have experience to talk about in using VCOs, designing PLLs, Filters, Amplifiers, and frequency multipliers.
Oscillator question PLS 相关文章:
