SAN ANTONIO -- Nov. 19, 2019 -- Mitigating ongoing threats to national security requires timely intelligence data, including signals intelligence (SIGINT) obtained through electronic surveillance.

Using digital techniques has caused a resurgence of interest in VLF — very low frequency — radio. Thanks to software-defined radio, you no longer need huge coils. However, you still need a suitable ...

Magnetic loop antennas are great if you are limited on space since they are just a potentially small loop of wire. The problem is, they are sharply tuned. You normally have an adjustment capacitor to ...