Adaptive antenna and radio

A device comprising:

• a controller to select a sub-band in a television white space frequency band;
• a controller interface to configure an antenna matching circuit based on the selected sub-band and to configure a bandpass filter based on the selected sub-band;
• and
• a receiver to receive a first signal in the selected sub-band through a first radio-frequency path from an antenna of the device, the first radio-frequency path including the antenna matching circuit and not including the bandpass filter, wherein the receiver is configured to measure a parameter of the received first signal;
• wherein the receiver is configured to receive a second signal in the selected sub-band through a second radio-frequency path from the antenna, the second radio-frequency path including the antenna matching circuit and the bandpass filter, and wherein the receiver is configured to measure a parameter of the received second signal, and
• wherein the controller is configured to determine whether the selected sub-band is usable based on the measured parameter of the received first signal, and the controller is configured to determine whether the selected sub-band is usable based on the measured parameter of the received second signal.