Differential-mode aperture-coupled patch antenna

A differential-mode feed circuit for an aperture-coupled patch antenna, the feed circuit comprising:

• a first port and a second port, the first and second ports configured to be located at opposite ends of an aperture of the aperture-coupled patch antenna, to cause the first port to receive a signal that is 180° offset from that received by the second port;
• a difference port between the first and second ports, a first electrical path length travelled by a signal from the first port to the difference port and a second electrical path length travelled by a signal from the second port to the difference port differing by an odd integer multiple of half a signal wavelength;
• and
• a sum port between the first and second ports, a third electrical path length travelled by a signal from the first port to the sum port and a fourth electrical path length travelled by a signal from the second port to the sum port being equal in path length.

A wireless communication device comprising:

• a wireless communication interface for processing transmission and reception signals;
• and
• an aperture-coupled patch antenna for communicating the transmission and reception signals, the antenna comprising:
• at least one radiating patch;
• a substrate supporting the first and second radiating patches, the substrate including:
• a first slot-shaped aperture for electromagnetic coupling of the reception signal from the at least one radiating patch to first and second receive ports;
• and
• a second slot-shaped aperture, orthogonal to the first aperture, for electromagnetic coupling of the transmission signal from a transmit port to the at least one radiating patch;
• a transmit feed circuit provided on the substrate for communicating the transmission signal to the transmit port, the first feed circuit being a single-ended feed circuit;
• and
• a receive feed circuit provided on the substrate for communicating the reception signal from the receive ports, the receive feed circuit being a differential-mode feed circuit;
• the receive feed circuit defining a difference port between the first and second receive ports, a first electrical path length travelled by a signal from the first receive port to the difference port and a second electrical path length travelled by a signal from the second receive port to the difference port differing by an odd integer multiple of half a signal wavelength;
• and
• the receive feed circuit defining a sum port between the first and second receive ports, a third electrical path length travelled by a signal from the first receive port to the sum port and a fourth electrical path length travelled by a signal from the second receive port to the sum port being equal in path length.