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.
You have a ground plane covering the entire top layer? I hope you took that into consideration when designing your microstrip transmission lines. Also, you really need to tie the top and bottom ground layers together with a bunch of vias.
I won't pretend to be an expert, but that layout looks quite horrible to me. In particular, the output trace has a odd 45° join that I cannot see any reason for, and the stub to the 47 nH inductor is a bad idea.
You should rotate the amplifier 90° counter-clockwise, so the signal travels straight down from the top input to the bottom output. Right now, the signal makes two 90° turns for absolutely no reason.
Also: Place the bypass caps as close as physically possible to the device.
Furthermore, you have a bottom ground plane (the bottom layer pretty much has to be a ground. It is a ground, right?) That being the case, why are you routing any ground traces?
As an example, here is a mini-circuits eval-board for a similar part:
Some things to note:
LOTS of vias. Each ground connection uses multiple vias. Multiple vias are critical for low-impedance ground connections.
The controlled-impedance trace is routed right up to the part. If you have to reduce the trace to connect to the part, do it as close as possible, and ideally have a gradual taper.
Here is another, similar eval board:
In this case, the amplifier is in a SOIC-8 package, but the same things are true. There are 14 vias just for the amplifier!
In general, I'd say avoid the top copper pour unless you absolutely need to have it for properly controlling impedance. The top copper results in something called a coplanar waveguide, which means you can get away with slightly narrower traces for the same impedance, but it also means you need to tie the two grounds together.
Here is the eval-board for a mini-circuits SP6T RF switch that uses coplanar waveguides:
Note the MASSIVE number of vias. This is called "via stitching", and is required for proper RF behaviour when using coplanar waveguides above a ground-plane.
Update:
Doodle-CAD layout:
It's crude, but it's a first-past at how I'd lay out that board. I don't pretend to be an expert, but I've had decent success with the boards I've done.
Critically, the grounding is important. It's pretty difficult to have too good a ground, but it's easy to have too poor a ground, so err on the side of "Ground all the things".
The one potential concern here is that grounding like this can cause issues with soldering during assembly. I've done even more aggressive via stitching, and assembled the resulting boards without issue using the hot-plate reflow practice, but depending on your assembly process, the huge thermal connection to the ground-plane could be an issue for solderability.
Best Answer
Polarization and phase are not the same thing.
Polarization is the plane that the electric field oscillates in (the magnetic field is at right angles to it). In a vertical antenna the electric field is vertically oriented, so the EM wave will also have vertical polarization. Polarization angle is not changed by reflection, so a vertically polarized wave will still be vertically polarized when reflected (thus "the polarization of the reflected waves must be as indicated").
Phase is the relative angle in time between waves. If two waves are going up and down at exactly the same time then they are 'in phase', and when combined their amplitudes will add ('constructive' interference). If they are 'out of phase' then the combined signal will not be as strong ('destructive' interference), the weakest point being when the phase difference is 180°.
Reflection may cause a phase change depending on the angle of reflection, polarization of the incident wave (vertical E field is close to in phase at angles over about 30°, horizontal E field is always 180° out of phase) reflecting material and frequency. But phase also changes with distance, so two waves that start out in (or out) of phase may not be so after traveling over paths with different lengths. As the reception point is moved the the phase difference will continually change from constructive to destructive and back, so the signal will fade in and out.