Timing adjustment method for radar, and radar apparatus having automatic timing adjusting function
AssigneeFujitsu Ten Limited
InventorNobukazu Shima
Life of this patent
Estimating the term…
Abstract
On/off timing of an amplifier and timing of antenna selection are accurately adjusted. When adjusting the on/off timing of the amplifier, modulation of a transmit signal is stopped, and a switch is set so as not to select any one of the antennas, thereby totally reflecting the transmit signal; in this condition, the timing is controlled so that the average value of the output level of a mixer becomes a minimum. When adjusting the antenna selection timing, modulation of the transmit signal is stopped, and a reflective object is placed in close proximity to the antenna; in this condition, the timing is adjusted so that the average value of the output level of the mixer becomes a maximum.
Claims13
A timing adjustment method of adjusting timing for turning on and off a transmitting amplifier and timing for antenna selection in a 1:N switch, for use in a radar comprising the transmitting amplifier for amplifying a transmit signal, a receiving amplifier for amplifying a received signal, a duplexer connected to an output side of said transmitting amplifier and an input side of said receiving amplifier, a number N of antennas, the 1:N switch, provided between said duplexer and said N antennas, for selecting one of said N antennas and connecting said selected antenna to said duplexer, and a mixer for mixing a portion of said transmit signal with said received signal, said method comprising the steps of:
- (a) stopping modulation of said transmit signal;
- (b) setting said receiving amplifier always ON;
- and
- (c) adjusting, after said steps (a) and (b), the timing of said antenna selection in said 1:N switch relative to the turning on and off of said transmitting amplifier, based on a voltage level output from said mixer.
A radar apparatus having an automatic timing adjusting function, comprising:
- a transmitting amplifier for amplifying a transmit signal;
- a receiving amplifier for amplifying a received signal;
- a duplexer connected to an output side of said transmitting amplifier and an input side of said receiving amplifier;
- a number N of antennas;
- a 1:N switch, provided between said duplexer and said N antennas, for selecting one of said N antennas and connecting said selected antenna to said duplexer;
- a mixer for mixing a portion of said transmit signal with said received signal;
- a unit stopping modulation of said transmit signal;
- a unit setting said receiving amplifier always ON;
- a unit generating a time average of a voltage level output from said mixer;
- and
- a unit adjusting, after stopping said modulation and setting said receiving amplifier always ON, the timing of said antenna selection in said 1:N switch relative to the turning on and off of said transmitting amplifier so that said time average becomes maximum.
Dependencies are inferred from the claim text.