I have InnoSenT SMR-314 and SMR-334 radar sensors that have quite wide horizontal radiation pattern of over 100 degrees (see datasheet on page 3). I would like to make the sensors far more directional - thinking about 15 degrees or so. Is it possible to mount some kind of antenna on top of the sensor to solve this issue? I want a low-cost solution - will a 3d printed horn antenna work?

The radar sensor is a SMT device and will be soldered on a PCB. From the physical point of view I wonder what king of mount would be needed for the horn antenna to work. The idea is to mount a single antenna to the whole sensor and make the hole in antenna flange big enough so that whole sensor fits in there. Also not sure whether the antenna needs to be grounded to the PCB or can be left unconnected.

  • \$\begingroup\$ Did you find a solution ? \$\endgroup\$
    – Ktc
    Jun 21, 2019 at 23:13

1 Answer 1


Yes, what you suggest is possible.

I used to work on a 60 GHz radar solution and there we designed horns and lenses made from plastic, some of which were 3D printed. Both were used to "focus" the radar beam. That radar product is a chip (IC) with build-in antennas so these antennas were quite small. That makes the EM waves behave almost as if they were all coming from one spot.

A challenge with your antennas will be that the antennas are distributed over a larger area. Not all antennas can be in the "focal point" of the lens or horn at the same time.

You might also want to contact InnoSenT and ask them if they have a radar product that has a more focused beam.

A horn antenna generally has a coax or transmission line input and that will have a shield which needs to be connected to ground. So the antenna indeed will require a ground connection.

  • \$\begingroup\$ I wonder if a PCB board with one big ground plane and milled openings mounted at a few mm distance from the original board would already have the desired effect. Or two such boards, stacked. \$\endgroup\$
    – Janka
    Sep 15, 2018 at 22:49

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