looking for micropower 5.9 GHz oscillator?

[biff44]

Searching for an oscillator chip (maybe with external ceramic resonator), or super low power PLL/VCO for use in the 5.9 GHz ISM band. Was hoping to find some sort of cmos chip that maybe could run 2.7V and 1 or 2 mA. Any ideas?

I am getting scared by things like SKY73134 chip guzzling 120 ma!

 

[jiripolivka]

Searching for an oscillator chip (maybe with external ceramic resonator), or super low power PLL/VCO for use in the 5.9 GHz ISM band. Was hoping to find some sort of cmos chip that maybe could run 2.7V and 1 or 2 mA. Any ideas?

I am getting scared by things like SKY73134 chip guzzling 120 ma!

Check Hittite HMC 431 VCO. I doubt anyone offers a better chip. Who would need a micropower VCO? You could design yours if you get a suitable dielectric resonator.

 

[biff44]

thanks, that is getting closer, 23 mA.

Was wondering how low a current draw I could get with a LNA fet and a ceramic transmission line resonator? I hate doing non-mimic oscillators in a production run, due to the "tuning" needed aspect, especially at 6 GHz, but that may need to be the way. Surprised I have not found any cmos type oscillators yet, like a ring osiclllator, at 6 ghz. lots of research papers, no parts in-stock anywhere

 

[jiripolivka]

thanks, that is getting closer, 23 mA.

Was wondering how low a current draw I could get with a LNA fet and a ceramic transmission line resonator? I hate doing non-mimic oscillators in a production run, due to the "tuning" needed aspect, especially at 6 GHz, but that may need to be the way. Surprised I have not found any cmos type oscillators yet, like a ring osiclllator, at 6 ghz. lots of research papers, no parts in-stock anywhere

MMIC chips are only developed to a serious demand on the market. Who really needs an ultra-low power oscillator, and for what purpose?

You can try design yours if you wish but I do not see a lot of use for such device. You can use a lower frequency oscillator and multiply the frequency. Years ago I needed a stable 800 MHz low-power signal, so I used a quartz oscillator and a 74F04 hex gate as a multiplier plus a filter. It worked well as a calibration signal for a satellite beacon receiver.

 

[biff44]

My hobby interests do not include microwave engineering! So trust me when I say there is significant commercial impetus for needing a ultralowpower oscillator.

 

[jiripolivka]

My hobby interests do not include microwave engineering! So trust me when I say there is significant commercial impetus for needing a ultralowpower oscillator.

Maybe, but you did not reveal to me any purpose of such massive demand for ultralow-power oscillator chips. Tell Hittite about it, they can do.

 

[BigBoss]

I'm following the discussion and I believe it's not possible to design any oscillator at that frequency and in that current range because of very low Gm value.
Otherwise, Barkhausen criteria can not be maintained.Remember a simple model of an oscillator to start-up Gm=Rp , Gm>Rp to sustain the oscillation.
If we consider 2mA current consumption, Gm value will be approximately-for a E-Mode pHEMT device which has a 065V Vt value- 3mS !!
So, theoretically it makes Rp=333 Ohm or greater.I didn't consider any other loss factors (just Gm,Rp approximation).
It sounds tough..

 

[jiripolivka]

I'm following the discussion and I believe it's not possible to design any oscillator at that frequency and in that current range because of very low Gm value.
Otherwise, Barkhausen criteria can not be maintained.Remember a simple model of an oscillator to start-up Gm=Rp , Gm>Rp to sustain the oscillation.
If we consider 2mA current consumption, Gm value will be approximately-for a E-Mode pHEMT device which has a 065V Vt value- 3mS !!
So, theoretically it makes Rp=333 Ohm or greater.I didn't consider any other loss factors (just Gm,Rp approximation).
It sounds tough..

Many years ago I designed a MESFET oscillator with a coaxial resonator for 5.6 GHz. I used an experimental MESFET made by Czech Tesla which required an adjustable RF feedback to oscillate. Later I used a Siemens MESFET which was better. I needed 3...5 VDC, 5 to 15 mA, the output was 8 dBm approx.
For a micro-power I once made a tunnel-diode oscillator at 5 GHz, the output was -13 dBm, DC input was 0.6 V, 2 mA. I doubt such (Russian)tunnel diodes are still available.

 

[tony_lth]

The hotest domian wearable device may need that for WLAN application. I just guess.

 

[biff44]

well I am seeing a ton of CMOS gate type LC coupled oscillators at micropower. A few discrete oscillators too, like this one

https://www.armms.org/media/uploads/1326110877.pdf

So less than 1 mw DC consumption is possible, and <2.7V DC operation is very real (2.7v is the discharged voltage of a single LiPo cell)