Tamperproof 169 MHz antennas keep AMR applications running

In a previous blog entry, I have discussed how due the size of the wavelength at 169 MHz, it is incredibly difficult to design an embedded antenna with any reasonable performance (actually yesterday I saw an "embedded" 169 MHz antenna with an incredible -17 dBi gain - yes minus 17 dBi!!!), so typically customers are looking at options to externally mount 169 MHz antennas as this is the only reasonable way to go.

From standard product portfolios, these will typcially include connector mounted helical antennas such as the H169-SMA antenna or wall-mounted omni antennas such as the WMO-169-WMB. The drawback with both antennas are connected to the radio or terminal via a coaxial cable or connector that may be easily unscrewed should somebody wish to detatch the antenna. If the antenna is not secured in any way, it does leave the application open to be tampered with, damaged or vandalised all via the external antenna.

One solution is to consider a permanent-mount through-hole 169 MHz antenna solution, where the 169 MHz antenna is permanently attached to the terminal via an integrated stud and secured with a washer/nut on the underside of the enclosure. In these cases, the antenna should be custom-tuned to the application as a groundplane is still required and groundplane sizes vary from product to product. An example of this permanent mount antenna is the WCO-169 antenna:

WCO-169 antenna with N-Female (through-hole) connector

With an O-Ring in the base of the antenna body which forms a waterproof seal against the enclosure, the WCO-169 is a robust, discrete and secure method of mounting an external 169 MHz antenna.

If you are interested in looking more closely at the WCO-169 and the possibility to tune the antenna to your application, please feel free to contact us at sales@ead-ltd.com. The H169-SMA and the WMO-169-WMB antennas are in stock and can be purchased via our webshop at www.connextech.co.uk.