Collision avoidance transmit system with autocalibration
First Claim
1. A calibration method for a transmitter having a first, a second, a third and a fourth element circumferentially positioned with a 90 degree spacing in an antenna array such that the first and the third elements are oppositively positioned and the second and the fourth elements are oppositively positioned, the first, the second, the third and the fourth element being selectively connectable through a first, a second, a third and a fourth channel, respectively, of components to a transmitter or to a first input of a phase detector, the transmitter being connected to the second input of the phase detector, comprising the steps of:
- determining the phase difference between a first and a third channel by transmitting a signal between the first element and a first element adjacent the first and third elements to obtain a first phase detector output, by transmitting the signal between the third element and the first element adjacent the first and third elements to obtain a second phase detector output and by inserting a first phase shift in the third channel such that the first and second phase detector outputs are equal;
determining the phase difference between a second and fourth channel by transmitting between the second element and a first element adjacent the second and fourth elements to obtain a third phase detector output, by transmitting between the fourth element and the element adjacent the second and fourth elements to obtain a fourth phase detector output and by inserting a second phase shift in the fourth channel such that the third and fourth phase detector outputs are equal;
transmitting between the first and third elements with the first phase shift inserted into the third channel to obtain a fifth phase detector output; and
transmitting between the second and fourth elements with the second phase shift inserted into the fourth channel to obtain a sixth phase detector output and inserting a third phase shift in the second channel such that the fifth and sixth phase detector outputs are equal.
1 Assignment
0 Petitions
Accused Products
Abstract
A transmit system for collision avoidance systems having autocalibration. A four element antenna array is provided. Each element is selectively connectable to a transmitter through a power divider and a isolator. Three of the elements further have a programmable phase shifter in line to the transmitter. A phase detector having a first input selectably connectable to one of the elements and a second output connected to the transmitter is provided. By selectively connecting one element to the transmitter and one element to the phase detector and then selectively programming the appropriate phase shifters, the differentiated phase delay in each channel of components associated with an antenna element can be calibrated.
54 Citations
12 Claims
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1. A calibration method for a transmitter having a first, a second, a third and a fourth element circumferentially positioned with a 90 degree spacing in an antenna array such that the first and the third elements are oppositively positioned and the second and the fourth elements are oppositively positioned, the first, the second, the third and the fourth element being selectively connectable through a first, a second, a third and a fourth channel, respectively, of components to a transmitter or to a first input of a phase detector, the transmitter being connected to the second input of the phase detector, comprising the steps of:
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determining the phase difference between a first and a third channel by transmitting a signal between the first element and a first element adjacent the first and third elements to obtain a first phase detector output, by transmitting the signal between the third element and the first element adjacent the first and third elements to obtain a second phase detector output and by inserting a first phase shift in the third channel such that the first and second phase detector outputs are equal; determining the phase difference between a second and fourth channel by transmitting between the second element and a first element adjacent the second and fourth elements to obtain a third phase detector output, by transmitting between the fourth element and the element adjacent the second and fourth elements to obtain a fourth phase detector output and by inserting a second phase shift in the fourth channel such that the third and fourth phase detector outputs are equal; transmitting between the first and third elements with the first phase shift inserted into the third channel to obtain a fifth phase detector output; and transmitting between the second and fourth elements with the second phase shift inserted into the fourth channel to obtain a sixth phase detector output and inserting a third phase shift in the second channel such that the fifth and sixth phase detector outputs are equal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification