EMRFD Message Archive 5211

Message	Date	From	Subject
5211	2010-09-21 11:55:59	Weddig, Henning-C...	AW: [emrfd] X-Mode Mixer
Chris, why doe You use lower LO power for the Schottky diodes? Is it only that they have lower on-voltages?? What happens if the LO power is varied i.e. does the OIP3 increase at higher LO power?? Henning Weddig DK5LV ________________________________ Von: emrfd@yahoogroups.com im Auftrag von Chris Trask Gesendet: Di 21.09.2010 20:41 An: emrfd@yahoogroups.com Betreff: Re: [emrfd] X-Mode Mixer The second batch of Schottky diodes arrived this morning, and here are the performace comparisons: Diode BAV70 BAT54C HSMS-2804 LO Level 2.0V 1.0V 1.0V Isolation RF to IF -40dB -47dB -46dB IF to RF -38dB -47dB -47dB LO to IF -47dB -59dB -60dB LO to RF -57dB -67dB -90dB OIP3 +22dBm +18dBm >+20dBm Conversion Gain -5dB -4dB -6.5dB I'm a bit surprised that the conversion gain is lower with the HSMS-2804 diodes. I'm going to get some HSMS-2814 diodes later as they have a much lower dynamic resistance and junction capacitance. Chris Trask N7ZWY / WDX3HLB Senior Member IEEE http://www.home.earthlink.net/~christrask/ ------------------------------------ Yahoo! Groups Links
5212	2010-09-21 12:30:46	ehydra	Re: AW: [emrfd] X-Mode Mixer
I'm not an expert in mixers, but is this the first performance data on the net for various diode types and LO powers? - Henry -- ehydra.dyndns.info Weddig, Henning-Christof schrieb: > Chris, why doe You use lower LO power for the Schottky diodes? Is it only that they have lower on-voltages?? > What happens if the LO power is varied i.e. does the OIP3 increase at higher LO power?? > Henning Weddig > DK5LV > > ________________________________ > > Von: emrfd@yahoogroups.com im Auftrag von Chris Trask > Gesendet: Di 21.09.2010 20:41 > An: emrfd@yahoogroups.com > Betreff: Re: [emrfd] X-Mode Mixer > > > > > The second batch of Schottky diodes arrived this morning, and here are > the performace comparisons: > > Diode BAV70 BAT54C HSMS-2804 > LO Level 2.0V 1.0V 1.0V > Isolation RF to IF -40dB -47dB -46dB > IF to RF -38dB -47dB -47dB > LO to IF -47dB -59dB -60dB > LO to RF -57dB -67dB -90dB > OIP3 +22dBm +18dBm >+20dBm > Conversion Gain -5dB -4dB -6.5dB > > I'm a bit surprised that the conversion gain is lower with the HSMS-2804 > diodes. I'm going to get some HSMS-2814 diodes later as they have a much > lower dynamic resistance and junction capacitance.
5214	2010-09-21 12:42:44	Chris Trask	Re: AW: [emrfd] X-Mode Mixer
> > I'm not an expert in mixers, but is this the first performance data on > the net for various diode types and LO powers? > Could be. Couldn't find any such comparisons myself. Chris Trask N7ZWY / WDX3HLB Senior Member IEEE http://www.home.earthlink.net/~christrask/
5215	2010-09-21 13:03:45	ehydra	Re: AW: [emrfd] X-Mode Mixer
Makes me wonder, and this a second: > BTW: The best performance with the silicon diodes was with a > squarewave LO, and with the Schottky diodes a sinewave LO worked best. - Henry -- ehydra.dyndns.info Chris Trask schrieb: >> I'm not an expert in mixers, but is this the first performance data >> on the net for various diode types and LO powers? >> > > Could be. Couldn't find any such comparisons myself.