Tupavco Panel Antenna TP-24-20-18 Teardown

In eventual hope for getting on 2.3 GHz, I picked up a pair of very low cost surplus panel antennas originally intended for SISO 2.4 GHz ISM operation. These were likely for WISP or other internet range extension use. I'm going to presume that they're broadband enough to extend down into the narrowband amateur segment, but maybe I'll get the chance to test that before applying much power.

Blank, smudged radome of a TP-24-20-18 antenna

The pamphlet included with the pair of antennas indicate that they are 20 dBi gain and 18° beamwidth in both directions. Over the specified 2400-2483 MHz they should have a VSWR <1.5:1, F/B >25 dB, and 50 W input capability. The connector is N female, overall dimension 298*298*45 mm (just under a square foot), 1.35 kg, reflector of aluminum alloy, and radome of ABS.

It's a more interesting device from other angles and on the inside for sure! 

Mounting and reflector side of the antenna showing off the specs label and N connector

I had popped this one open before starting taking pictures. There are a dozen Philips-head screws and a round of silicone on the aluminum to hold the radome. To keep things lined up, I added a couple markings for reassembly. Not that it'll ever be weatherproof again with the silicone bead split.

Separation of the backplate from the radome at one corner

Opened radome showing foam cushions and the 4x4 array of patch antenna elements

The gain implementation is by matched-phase drive of flag- or book-shaped planar dipoles. A two-sided FR4 PCB is used with one pole of each dipole on each side.

Close up of a dipole flag on one edge

Production custom tuning tabs soldered on the first pair of lines out of the connector

Side view of the foam spacer and remaining silicone on the reflector

The whole backplate acts as a controlled-distance reflector and helps set the F/B ratio. A bigger reflector might provide more performance at the cost of expanding the panel area. Presuming that this was for end-user sites, then the side/back lobe performance wouldn't be as critical compared to central tower locations with higher transceiver density.

Now to get the pesky SDR working and plan out antenna switching…

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