Stamped metal antennas are mounted directly on the PCB or on the housing wall with a cable.
A stamped antenna has a metallic strut. A carrier material is not necessary. The metal provides the necessary mechanical stability. This technique can be used to develop different types of antennas.

Features of stamped metal antennas:

• can also be etched or water cut;
• can be shaped and bent to be embedded in a small IoT device;
• can be mounted vertically, horizontally or coplanar with the host PCB;
• can be mounted flat or curved;
• can be supplied with various cable lengths;
• offer an omnidirectional radiation pattern;
• are cheaper than externally mounted antennas;
• achieved high power levels without the cost of an external antenna.

As already documented in the study on Low-Cost DIY PCB antennas, the size of the main PCB together with its mass surface used has a direct influence on the performance of an antenna. Stamped antennas require a sufficiently large mass surface.

To avoid unpleasant surprises, a test setup with the flexible antenna in the plastic enclosure of the planned IoT device with a test board is recommended. This test board only requires two coaxial connectors. One coaxial connector is used to connect the antenna. The second coaxial connector is used to generate a test signal with the Vector Network Analyser and measure the return loss. You can read more about this test setup here.