High freq. quadrature source generation?
Could anyone give me a method to generate the 3GHz quadrature source? Since I need to use the quadrature LO signal to test my quadrature upmixer. I just find signal generator just generates baseband (low frequency) quadrature source.
Thanks,
wccheng
You can design a PLL based synthesizer for generating a LO for your application...
For this you need to choose a PLL chip (like ADF4153 from Analog Devices) and a VCO (like from ZCOMM)....
For PLLs, PLL Synthesizers / VCOs | RF / IF ICs | Analog Devices
For VCOs, VCO Search by Center Frequency or Part Number
This may be one time investment for you and once you design your Synthesizer you can tune it to your own frequency...
From National Semiconductor you have LMX2531 which has integrated VCO..this can be done with low cost
Link : LMX2531 Integrated PLLatinum PLL+VCO Family
You can use any synthesizer to generate 3GHz then place a circuit to split equally but with phase difference of 90 deg.
job is done
If you use differential divider by 2 circuit and then if you put a Polyphase filter to correct the phases, you may obtain impressive quadrature signals.
But your VCO should work 2 times higher than operatiing frequency..
Or design a quadrature VCO directly but it's difficult to realize..
