MIPRO - Knowledge | Wireless Knowledge

The transmission range of a wireless system is determined by the transmitter's output power and the receiver's sensitivity. Ideally, if a user can increase the output power of the transmitter, they should be able to increase their system's range. However, this is usually not possible since the transmitter's output power is already preset during production. In addition, an increase in transmitting power is hindered by wireless regulations, interference between multiple systems and a shortage of transmitter operating hours due to higher battery voltage consumption. The alternative is to increase the sensitivity level of the receiver. Theoretically speaking, the transmitting range doubles with an increase of 6dB in sensitivity. In real life, however, the user cannot easily adjust the sensitivity level since it is integrated with the antenna. In application, since the signal is received via the receiver's antenna, the proper selection of an antenna is vital to the system's overall range and performance.

A mountable antenna is carefully designed and selected to match the input impedance of the receiver while still offering the user a degree of flexibility. MIPRO's receiver antennas have several designs:

1/4-wave, single rod antenna. It is omni-directional and rated at 50ohms. It is a metallic dipole antenna designed to mount directly on the receiver antenna connectors and provides adequate operating range and sensitivity level in most (many?) applications.

1/2-wave antenna. It functions like a dipole antenna, having standard 2.4dBi, 50ohm and omni-directional characteristics. It is mounted directly on the receiver antenna connectors and provides good operating range and a higher sensitivity level.

AT-70 Ground Plane Antenna:

It provides a significant gain over the 1/4-wave monopole. The best impedance match is provided when the radials are angled downward from the vertical at a 45-degree angle, causing a 1/2-wave dipole antenna effect. A ground plane antenna exhibits a circular coverage pattern, perpendicular to the vertical element. The antenna should be positioned so that the radials are closest to the nearest boundary such as a central location on the floor, wall or ceiling and functions best when inverted.

AT-90R UHF Log Periodic Dipole Array Antenna:

Optimized for 600MHz~1GHz, it has a 4~6dBi effect, 80°E-Plane & 140°H-Plan, built-in 13dB low-noise amplifier and 1.6dB extremely low analog booster. It enhances coverage and improves range. It is a multi-element, directional antenna that operates over a wide frequency range. The pickup pattern is sensitive in a single direction, making the positioning critical. Waterproof, it is ideally suited for indoor or outdoor use and for installation in difficult multiple wireless system environments.

AT-90R UHF Active Log Periodic Dipole Array Antenna:

At AT-90T built-in 13dB or more gain, 2.5dB or less low noise indicator booster, it provides 17dBi gain to reconcile the signal loss of long transmission cable. Waterproof, it is ideally suited for indoor or outdoor use and for installation in difficult multiple wireless system environments.