- How do I contact an Applications Engineer?
- How do I solder a VCO onto the PCB?
- Is it important to load the output to the VCO properly?
- The output power coming out of the VCO seems lower than what Z-Comm has specified. Is that a problem and are there any suggestions?
- I’m designing a modem whose BER increases when the VCO picks up stray perturbations. Any suggestions on how to minimize microphonic pickup?
- Can you supply me with test data on the VCO product I have?
- Does Z-Communications, Inc. build custom VCOs and PLLs? If so, what information is needed?
- Can I use several VCOs for multiband switching?
- Should a Z-Comm VCO work at zero volt tuning voltage?
- Will Z-Comm VCOs operate on a higher/lower supply voltage than the one specified?
- Can the shields of an existing VCO be trimmed lower to fit my design?
There are a number of ways you can reach one of our applications experts. You can contact us via our contact page; fax us at (858) 486-1927; or call us at (858) 621-2700 between the hours of 7:30 and 4:30 PST. All questions and comments will be answered in a timely manner. << back to top
You can solder a VCO onto a PCB using either of two very simple procedures. The first step is a manual process that is explained in application note 107. You may also use a convection oven to solder the device securely onto the PCB. That process is outlined in application note 112. << back to top
Loading the output to the VCO properly is probably the key feature of allowing the VCO to meet the specifications on the data sheet. Application note 102 can delineate the proper process for loading. << back to top
Often, low output or fluctuations in output power across the frequency band are attributed to a less than optimum output match at the RF terminal of the VCO and/or grounding problems. Ultimately, Z-Communications VCOs are designed to operate with a 1.67:1 VSWR (about 14 dB return loss) and, sometimes, the reactance at the output terminal needs to be investigated. Depending on the VCO, we recommend at least a 6 dB pad (resistive pi-pad network should suffice) of isolation along with a MMIC amplifier. In other words, there should be about 40 dB of reverse isolation. Furthermore, be sure that the VCO sits on a ground plane with a number of plated through holes (vias) spaced between 20 and 30 mils wide. Also, note the presence of soldermask can sometimes degrade VCO performance. Contact our Applications Engineering group for more information. << back to top
The VCO is a transducer because any mechanical signals present on the PCB will naturally be picked up by the VCO’s RF shield. One step towards minimizing the effect of microphonics in the loop would be to ensure that the VCO is adequately grounded. Another step would be to utilize polyester composition capacitors in the loop filter and supply lines instead of ceramic composition capacitors. << back to top
Since each VCO manufactured by Z-Communications, Inc. is tested before it is shipped, you can be assured that it is fully compliant to specifications. Please refer to the data sheets and applications notes. << back to top
Yes, you can use as many VCOs required to cover your frequency range as long as your design has enough power to drive all VCOs according to specs. For more information please see our application note AN-105. << back to top
Yes, all Z-Comm VCOs should operate at zero-volt tuning voltage. << back to top
A VCO will operate at a lower supply voltage, but it will show degradation and inconsistency in power and tuning range. We do not recommend higher supply voltage as it can destroy the components inside. << back to top
We may lower most of our shields on CLV series and V series up to .13” and our SMV series up to .08”. The CRO series will only be available in .22” due to its Coaxial Resonator. << back to top