mkeppler
Newbie level 3
Hi all,
I need to design a 6Ghz VCO. In a post on this board last year there was a question about designing a 5Ghz VCO. The link to that discussion is
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One response from board member "DJ" was as follows:
"Simple. Use BJT 681000 (of Nec)or its package or 420000 (Of @gilent).
Load the Emiter by an open stub or a capacitor. Load the base with a narrow line as an inductor ended with MaCom or Metalic or Micrometric varactor to the ground. You have to concider DC of course."
I'm new to VCO design so the above description is a bit vague for my needs. DJ if your still on here could you elaborate. Why is the emitter loaded with a capacitor? I assume the inductor and varactor on the base act as a resonator circuit. Does the LC circuit on the base set the frequency of oscillation or does it act in combination with other effects to set the frequency of oscillation? Information as basic as that would be helpful. Also, any design equations would be very helpful.
Thanks,
Marc
I need to design a 6Ghz VCO. In a post on this board last year there was a question about designing a 5Ghz VCO. The link to that discussion is
<>
One response from board member "DJ" was as follows:
"Simple. Use BJT 681000 (of Nec)or its package or 420000 (Of @gilent).
Load the Emiter by an open stub or a capacitor. Load the base with a narrow line as an inductor ended with MaCom or Metalic or Micrometric varactor to the ground. You have to concider DC of course."
I'm new to VCO design so the above description is a bit vague for my needs. DJ if your still on here could you elaborate. Why is the emitter loaded with a capacitor? I assume the inductor and varactor on the base act as a resonator circuit. Does the LC circuit on the base set the frequency of oscillation or does it act in combination with other effects to set the frequency of oscillation? Information as basic as that would be helpful. Also, any design equations would be very helpful.
Thanks,
Marc
