Microwave system design [materials-equipment hlp]

Hi brothers and sisters (alike),

I'm into designing a communications systems using microwaves, and I'm kinda new in this field. My team have already calculated and mapped our comm sites and have it profiled mapped, calculated link budgets, losses, system reliability...
etc. right now I'm assigned to choose the equipment that will be housed in the sites we planned... I'm reviewing some of the Andrew products (an RF communication company) ...

this is my point:

In a comm design, can you guys suggest some parameters or considerations to choose a certain equipment we have to use... eg. what are the pros and cons in waveguides for rectagular or elliptical, what TYPE of coax is appropriate, things like that....

I have no problems in choosing RF amplifiers, combiners or dishes since I have calculated to suit our requirements, so my main problem here is the TRANSMISSION LINES to be used


thanks in advance and peace!
the_risk_master

Main issue with transmission line is how much loss can you tolerate at your design frequency. If your receiver LNA is not mounted at the antenna, then every dB of cable loss will increase receiver noise figure by dB. For the transmitter, it is power wasted as heat.

how about in wave guides; what is the advantage or disadvantages in using a flexible or rigid , elliptical or rectangular waveguides?