Microwave antennas are those which are used for point-to-point (PTP) and point-to-multipoint (PTMP) wireless communications.
While a microwave is technically anything above 1 GHz, the frequencies used for this type of transmission are generally the 2.4 GHz and 5 GHz ‘unlicensed’ bands (also called the Sub-6 GHz bands), and then licensed bands from 6 to 42 GHz. Another group of frequencies known as mmWave are from 60 to 90 GHz which are used for very short range communication.
Point-to-Point antennas are designed to focus a tight beam of signal at the receiving antenna. Parabolic dish antennas are most commonly used in PTP microwave communication as the large reflector provides very high gain.
Point to Multipoint antennas generally use a sector antenna to provide a wide arc of coverage, often 65° or 90°, so that many receivers (often called subscribers) can connect back to the sector. Sector antennas are typically panel antennas constructed with an array of stacked dipoles or microstrip patches.
One of the most important characteristics of a microwave antenna is how well the antenna is isolated from other interfering transmissions. Because of the extreme sensitivity used to achieve modulations beyond 2048QAM, close attention needs to be paid to the antenna’s Cross-Polar Discrimination (XPD), Peak Gain, and Radiation Pattern Envelope (RPE). These characteristics form the basis of international microwave antenna regulatory constraints, such as those imposed by ETSI and FCC.