How Can I Design a 13MHz Sine Wave Signal Generator with 30-40V Output?

AI Thread Summary
Designing a 13MHz sine wave signal generator with a 30-40V output requires careful consideration of load characteristics, including impedance and current requirements. The discussion highlights the importance of matching the generator to the load to avoid output reduction and potential radiation issues. Common signal generators typically reach 20MHz but may not achieve the desired voltage without significant amplification. Suggestions include using a matching network and considering the use of MOSFETs to generate a square wave, which can then be filtered to create a sine wave. Overall, achieving the desired output may be complex for a hobbyist, making purchasing a ready-made solution a viable alternative.
TeeBeeBee
Messages
5
Reaction score
0
I am very new to circuit design so any help is much appreciated. I need to design a signal generator that will output about 30V-40V peak to peak at 13MHz (sine wave) If the signal generator is not able to, then I need some kind of amplifier. So far I have looked into Hartley and Colpitts oscilators and am not having any luck reaching my desired output. Any help or suggestions would really help. Thanks in advance
 
Engineering news on Phys.org
Is 13 MHz the only frequency the signal generator needs to produce?
What will the load be on the signal generator (how much current)?
Is the load strictly resistive or can it be capacitive or inductive?
Will the load be constant or variable and if variable by how much?
 
I would like to keep the frequency around 13MHz but if the output can be reached at lower/higher frequencies then the output takes priority. The load can be resistive, capacitive or inductive. The load is constant and I am not too sure about the current, but like to keep the current at a minimum though
 
Knowing how much current or better yet the impedance of the load is very important. If your load is connected by coax and the coax is more than about a meter and the load doesn't have the same impedance of the coax or the coax isn't the same as your signal generator, your output will be reduced. A VSWR meter can tell you if you are matched or not. If you aren't you can make of buy a matching network which you can adjust until you get a minimum reading on the VSWR meter.

Without seeing your circuit or knowing what your load is, I can't help you any more.

Will your signal be radiated? There are broadcast stations in the 12MHz frequencies, marine mobile around 13 MHz and radio astronomy above 13 MHz. A mismatch between generator and load as well as an improper ground can cause it to radiate. Recently two ham operators near Cleveland were fined $30,000 collectively for abusive radio transmissions.
 
Someone unskilled in the art is unlikely to fabricate such a generator cheaper than one can be purchased. Common signal generators reach 20 MHz, but are limited to about 20Vp-p when terminated into 50 ohms. It would require a 16 watt amplifier to barely achieve 40Vp-p into 50 ohms resistive, 32 watts for 25 ohms, and 8 watts into 100 ohms. So, knowing the load and being able to match to it is very important (see transmatch).
13.56 MHz is an ISM frequency reserved for equipment that might inadvertently radiate, so there is a convenient frequency nearby.

All of this is a bit much for a hobbyist to fabricate, but readily available to purchase.
 
A pair of mosfets, (as used in a switching power supply), would generate a square wave, that could then have a resonant tank circuit to remove the harmonics.
The OP specifies a sine wave. What level of harmonic content is acceptable?
 
Hi all I have some confusion about piezoelectrical sensors combination. If i have three acoustic piezoelectrical sensors (with same receive sensitivity in dB ref V/1uPa) placed at specific distance, these sensors receive acoustic signal from a sound source placed at far field distance (Plane Wave) and from broadside. I receive output of these sensors through individual preamplifiers, add them through hardware like summer circuit adder or in software after digitization and in this way got an...
I have recently moved into a new (rather ancient) house and had a few trips of my Residual Current breaker. I dug out my old Socket tester which tell me the three pins are correct. But then the Red warning light tells me my socket(s) fail the loop test. I never had this before but my last house had an overhead supply with no Earth from the company. The tester said "get this checked" and the man said the (high but not ridiculous) earth resistance was acceptable. I stuck a new copper earth...
I am not an electrical engineering student, but a lowly apprentice electrician. I learn both on the job and also take classes for my apprenticeship. I recently wired my first transformer and I understand that the neutral and ground are bonded together in the transformer or in the service. What I don't understand is, if the neutral is a current carrying conductor, which is then bonded to the ground conductor, why does current only flow back to its source and not on the ground path...
Back
Top