Abstract: An antenna includes a first antenna element and a second antenna element. The first antenna element and the second antenna element are configured to transmit and receive signals in a first band of frequencies and in a second band of frequencies. A first pair of delay lines is coupled to the first antenna element and a second pair of delay lines coupled to the second antenna element. A first delay line in the first pair of delay lines and the second pair of delay lines is configured to phase shift electrical signals coupled to the first antenna element and the second antenna element such that a first impedance of the antenna is approximately equal in the first band of frequencies and the second band of frequencies. A second delay line in the first pair of delay lines and the second pair of delay lines is configured to convert the first impedance to a second impedance.

Abstract: A positioning system includes a plurality of devices configured to exchange RF signals with one another. A first device periodically receives a message from each other device during time slots assigned them. The received message includes information representing a time of arrival at the other device of a respective message transmitted by the first device. A time of arrival of the message from each of the other devices is determined by the first device. The first device periodically transmits messages to the other devices, each transmitted message including information representing the determined time of arrival for at least one of the other devices. A range from the first device to each of a plurality of the other devices is determined as function of the determined time of arrival of the message from the other device and the time of arrival information in the message from the other device.

Abstract: A flow sensor for use in a harvester is disclosed. The flow sensor has a microwave transceiver for transmitting a microwave signal and receiving a reflected microwave signal, an in-phase mixer electrically connected to the microwave transceiver for combining the transmitted microwave signal and the reflected microwave signal and outputting an in-phase Doppler signal, a quadrature mixer electrically connected to the microwave transceiver for combining the transmitted microwave signal and a delayed reflected microwave signal and outputting the quadrature Doppler signal, and an electronic circuit electrically connected to the in-phase mixer and the quadrature mixer and having a flow rate output.

Abstract: A flow sensor for use in a harvester is disclosed. The flow sensor has a microwave transceiver for transmitting a microwave signal and receiving a reflected microwave signal, an in-phase mixer electrically connected to the microwave transceiver for combining the transmitted microwave signal and the reflected microwave signal and outputting an in-phase Doppler signal, a quadrature mixer electrically connected to the microwave transceiver for combining the transmitted microwave signal and a delayed reflected microwave signal and outputting the quadrature Doppler signal, and an electronic circuit electrically connected to the in-phase mixer and the quadrature mixer and having a flow rate output.