Electronic – the purpose of CB radio ground plane

cksa361, I am confused by your bounty because I am not sure what else you need answered except for the comment you left me, so I will answer that.

When you pick between different chip antennas you will normally not find one that is significantly better than another in every way unless a new process was developed. In most cases you will have to pick the one that better fits your application, and to you this will seem significantly better.

Radiation Strength

The larger one, Mica, has better radiation characteristics(more power out for the same power in). This means that for two transmitters radiating the same power, this antenna will get greater range. This also means the Mica antenna will receive from a source at a great distance much better.

Size

The Taoglas is smaller. This is self explanatory, if space is an issue, or if the odd size of the mica causes problems, the Taoglas wins.

Tuning

You will need to tune the matching circuit for the Mica one. For the Taoglas it seems they have a set matching circuit. This problem is approached in the question about measuring output impedance. This can be challenging if you do not have the right equipment. A mistuned antenna will severely hurt your range, if you cannot tune you may find the Taoglas will be easier to use.

Edit: I misread the datasheets, they both have reference designs. If you are going to vary your layout from the reference design (ie. You do not have room to do the exact say layout) on either antenna you will need to re-tune the circuit, as was linked in the paragraph with the strike-though.

I hope this helps.

This is a very complex issue, since it deals with EMI/RFI, ESD, and safety stuff. As you've noticed, there are many ways do handle chassis and digital grounds-- everybody has an opinion and everybody thinks that the other people are wrong. Just so you know, they are all wrong and I'm right. Honest! :)

I've done it several ways, but the way that seems to work best for me is the same way that PC motherboards do it. Every mounting hole on the PCB connects signal gnd (a.k.a. digital ground) directly to the metal chassis through a screw and metal stand-off.

For connectors with a shield, that shield is connected to the metal chassis through as short of a connection as possible. Ideally the connector shield would be touching the chassis, otherwise there would be a mounting screw on the PCB as close to the connector as possible. The idea here is that any noise or static discharge would stay on the shield/chassis and never make it inside the box or onto the PCB. Sometimes that's not possible, so if it does make it to the PCB you want to get it off of the PCB as quickly as possible.

Let me make this clear: For a PCB with connectors, signal GND is connected to the metal case using mounting holes. Chassis GND is connected to the metal case using mounting holes. Chassis GND and Signal GND are NOT connected together on the PCB, but instead use the metal case for that connection.

The metal chassis is then eventually connected to the GND pin on the 3-prong AC power connector, NOT the neutral pin. There are more safety issues when we're talking about 2-prong AC power connectors-- and you'll have to look those up as I'm not as well versed in those regulations/laws.

Tie them together at a single point with a 0 Ohm resistor near the power supply

Don't do that. Doing this would assure that any noise on the cable has to travel THROUGH your circuit to get to GND. This could disrupt your circuit. The reason for the 0-Ohm resistor is because this doesn't always work and having the resistor there gives you an easy way to remove the connection or replace the resistor with a cap.

Tie them together with a single 0.01uF/2kV capacitor at near the power supply

Don't do that. This is a variation of the 0-ohm resistor thing. Same idea, but the thought is that the cap will allow AC signals to pass but not DC. Seems silly to me, as you want DC (or at least 60 Hz) signals to pass so that the circuit breaker will pop if there was a bad failure.

Tie them together with a 1M resistor and a 0.1uF capacitor in parallel

Don't do that. The problem with the previous "solution" is that the chassis is now floating, relative to GND, and could collect a charge enough to cause minor issues. The 1M ohm resistor is supposed to prevent that. Otherwise this is identical to the previous solution.

Short them together with a 0 Ohm resistor and a 0.1uF capacitor in parallel

Don't do that. If there is a 0 Ohm resistor, why bother with the cap? This is just a variation on the others, but with more things on the PCB to allow you to change things up until it works.

Tie them together with multiple 0.01uF capacitors in parallel near the I/O

Closer. Near the I/O is better than near the power connector, as noise wouldn't travel through the circuit. Multiple caps are used to reduce the impedance and to connect things where it counts. But this is not as good as what I do.

Short them together directly via the mounting holes on the PCB

As mentioned, I like this approach. Very low impedance, everywhere.

Tie them together with capacitors between digital GND and the mounting holes

Not as good as just shorting them together, since the impedance is higher and you're blocking DC.

Tie them together via multiple low inductance connections near the I/O connectors

Variations on the same thing. Might as well call the "multiple low inductance connections" things like "ground planes" and "mounting holes"

Leave them totally isolated (not connected together anywhere)

This is basically what is done when you don't have a metal chassis (like, an all plastic enclosure). This gets tricky and requires careful circuit design and PCB layout to do right, and still pass all EMI regulatory testing. It can be done, but as I said, it's tricky.