I have learned that especially in RF circuits stray capacitance can mess circuits up. I have learned that breadboards are a major culprit for this. However I do not know really what it is. What is stray capacitance and second would this board generate stray capacitance?
Stray Capacitance and how it can be Avoided
prototypingRF
Related Solutions
Here's a picture of a board which had some headers forced into it which were too large, damaging the contacts:
The outer rows of the Sharpie'd area make intermittent contact, so we avoid the whole section. Notice that some of the numbers are rubbed off, and also notice the burnt spot at the top of the picture where something burned up.
The breadboard still has two other middle sections, and this section is only 20 rows tall, so that leaves 172 good rows. On a university budget, that doesn't merit replacing the board. If you are demonstrating breadboarded circuits to a client, you should probably replace the whole thing.
By the way, this board is at least 8 years old, and still works fine except for the indicated area. I've only been around it for three years, but no one has had any problems with it that I've heard of.
The big question is: what distance do you want to cover? The data sheet of the transmitter quotes a maximum range of 50 metres [about 150 ft]. Will you use that, or will the receiver be closer?
Any oscillating signal will radiate: the whole point of the USA's FCC is to limit the amount of annoying [or dangerous] EM radiation coming from devices. Depending on the range, and the presence of bulky metallic objects between transmit and receive, Your Mileage May Vary.
Antenna theory and design can be taught in depth by amateur radio enthusiasts, or groups like ARRL. For starters, a simple piece of wire about 20cm long can act like a "whip" antenna: keep it clear of grounded cases, and it should be enough to get you started. A second piece the same length can act as your receive antenna. Start with the circuits next to each other, make sure they work, then seperate them. If they stop working before reaching the seperation you want, THEN [and only then!] consider delving into antenna theory...
If you need more, I'd suggest TI's Application Note #AN058: http://www.ti.com/lit/an/swra161b/swra161b.pdf
Related Topic
- How to make prototype circuits that include microcontrollers, and avoid breadboard annoyances at high frequencies
- RF Projects – Using Copper Clad for RF Projects
- Electronic – Making prototypes with high speed SMD components
- Best Solution for Compact Wiring on Stripboard
- Electronic – How to determine voltage and current limit of protoboard
- PCB – How to Make Connections on PCB Holes Without Solder
Best Answer
Whenever two pieces of metal are near each other, there is capacitance between them. If there is a voltage difference between them, there will be some equal and opposite charges accumulated on the two "electrodes". Conversely, in order to establish a voltage difference between them you must supply enough charge produce that voltage.
So if your signal in your rf circuit travels along a metallic conductor (like a wire or PCB trace) and that conductor is near some other conductor (like pins of a chip, or the lid of your enclosure or mounting screws or whatever), there will be capacitance between those two objects. If that isn't capacitance that the designer intended to exist, then we call it "stray capacitance".
To be honest, usually in rf we design the signal paths to be reasonably well shielded from sources of stray capacitance, and so this isn't usually an issue (but I've never tried to do rf on a breadboard). It's more in precision analog design that I've seen problems with stray capacitance.