Rectify 500MHz Small Signal
in [Design]
|
From: MooseFET on 25 Sep 2009 20:45 On Sep 25, 9:13 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- Web-Site.com> wrote: > Anyone have clever ideas for rectifying a 500MHz sine wave, amplitude > say 50mV to 500mV peak-to-peak? > > Half wave is OK. > > 1mV accuracy is needed :-( > > Process is X-Fab XB06. > > Thanks! Do you also have a 499MHz signal handy? Do you want an analog voltage out or are you after a digital answer? If you jiggle the bias of a diode junction with the 500MHz, it will conduct more. If you jiggle the bias of a matched junction with a lower frequency and adjust the amplitude until it causes the same increase in conduction, you will know that the two waveforms are of equal amplitude. The adjustable amplitude waveform can be a multiplying DAC that you increase and decrease the number into it until the currents on the junctions match.
From: Bill Sloman on 25 Sep 2009 21:45 On Sep 25, 6:13 pm, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- Web-Site.com> wrote: > Anyone have clever ideas for rectifying a 500MHz sine wave, amplitude > say 50mV to 500mV peak-to-peak? > > Half wave is OK. > > 1mV accuracy is needed :-( > > Process is X-Fab XB06. Barrie Gilbert has had some ideas. His AD834 http://www.analog.com/static/imported-files/data_sheets/AD834.pdf could be used to square your 500MHz signal, which automatically rectifies it, though it leaves you with a lot of 1GHz ripple. If you wanted to do something cuter, you could phase-lock a nominally 1GHz voltage-controlled logic level oscillator to the 500MHz signal, and use it to generate two 500MHz signals mutually in quadrature - nominally square waves, but at least with well-defined amplitudes, and form in-phase and quadrature products. In a second order phase-locked loop, the quadrature output is integrated to control the VCO such that the quadrature output is precisely in quadrature with the incoming signal while the in-phase output can be used to drive another product detector (aka multiplier) whch gives you your rectified output. -- Bill Sloman, Nijmegen
From: Vladimir Vassilevsky on 25 Sep 2009 21:49 Tim Wescott wrote: > On Fri, 25 Sep 2009 09:13:53 -0700, Jim Thompson wrote: > > >>Anyone have clever ideas for rectifying a 500MHz sine wave, amplitude >>say 50mV to 500mV peak-to-peak? >> >>Half wave is OK. >> >>1mV accuracy is needed :-( >> > Make two identical paths, each with a diode, that lets you measure the DC > current from the diode to ground. The 1mV accuracy requirement rules out the solutions with matched diodes, not mentioning the unmatched ones. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com
From: Nico Coesel on 26 Sep 2009 07:09 Bill Sloman <bill.sloman(a)ieee.org> wrote: >On Sep 25, 6:13=A0pm, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- >Web-Site.com> wrote: >> Anyone have clever ideas for rectifying a 500MHz sine wave, amplitude >> say 50mV to 500mV peak-to-peak? >> >> Half wave is OK. >> >> 1mV accuracy is needed :-( >> >> Process is X-Fab XB06. > >Barrie Gilbert has had some ideas. His AD834 > >http://www.analog.com/static/imported-files/data_sheets/AD834.pdf > >could be used to square your 500MHz signal, which automatically >rectifies it, though it leaves you with a lot of 1GHz ripple. > >If you wanted to do something cuter, you could phase-lock a nominally >1GHz voltage-controlled logic level oscillator to the 500MHz signal, >and use it to generate two 500MHz signals mutually in quadrature - >nominally square waves, but at least with well-defined amplitudes, and >form in-phase and quadrature products. > >In a second order phase-locked loop, the quadrature output is >integrated to control the VCO such that the quadrature output is >precisely in quadrature with the incoming signal while the in-phase >output can be used to drive another product detector (aka multiplier) >whch gives you your rectified output. How about a s&h, a 7 bit ADC, peak hold register and a 6 bit DAC? -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... "If it doesn't fit, use a bigger hammer!" --------------------------------------------------------------
From: Jim Thompson on 26 Sep 2009 11:40
On Sat, 26 Sep 2009 11:09:43 GMT, nico(a)puntnl.niks (Nico Coesel) wrote: >Bill Sloman <bill.sloman(a)ieee.org> wrote: > >>On Sep 25, 6:13=A0pm, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- >>Web-Site.com> wrote: >>> Anyone have clever ideas for rectifying a 500MHz sine wave, amplitude >>> say 50mV to 500mV peak-to-peak? >>> >>> Half wave is OK. >>> >>> 1mV accuracy is needed :-( >>> >>> Process is X-Fab XB06. >> >>Barrie Gilbert has had some ideas. His AD834 >> >>http://www.analog.com/static/imported-files/data_sheets/AD834.pdf >> >>could be used to square your 500MHz signal, which automatically >>rectifies it, though it leaves you with a lot of 1GHz ripple. >> >>If you wanted to do something cuter, you could phase-lock a nominally >>1GHz voltage-controlled logic level oscillator to the 500MHz signal, >>and use it to generate two 500MHz signals mutually in quadrature - >>nominally square waves, but at least with well-defined amplitudes, and >>form in-phase and quadrature products. >> >>In a second order phase-locked loop, the quadrature output is >>integrated to control the VCO such that the quadrature output is >>precisely in quadrature with the incoming signal while the in-phase >>output can be used to drive another product detector (aka multiplier) >>whch gives you your rectified output. Of course, see my WVB receiver (on my website, SED page), dated 1974. Just ducky when you have ample headroom (�5V supplies). I have a single supply, minimum operating at +2.7V And Gilbert cells aren't all that accurate without lots of voltage an on-chip trimming... I need accuracy at small signals. > >How about a s&h, a 7 bit ADC, peak hold register and a 6 bit DAC? Dream on ;-) ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | LOSE the WUSS BRING BACK BUSH |