| 摘要 |
PURPOSE:To avoid a change of beam directional angle even to the variations of frequency, by using a phase shifter having specific frequency characteristics. CONSTITUTION:When an electric wave of a frequency (f) is fed through an input/output terminal 5, the electric waves are radiated as conventional from radiators 1-1-1-4 with a beam directional angle theta. When an electric wave of a frequency (f+DELTAf) is fed through the terminal 5, the electric waves having a phase difference equivalent to a phase degree of phi+DELTAphi between adjacent radiators are radiated from radiators 1-1-1-4 via phase shifters 6-1-6-3. In this case, the phase shifter has the frequency characteristics of DELTAphi=(DELTAf/f)phi, where phase degree phi=(2pidf/c)sintheta, frequency (f), changing degree DELTAphi of phase, and changing degree DELTAf of frequency respectively. Therefore phi+DELTAphi= 2pid(f+DELTAf)/c sin(theta+DELTAtheta) is satisfied, where the beam directional angle theta+DELTAtheta. If the above equation is substituted here, phi=(2pidf/c)sin(theta+DELTAtheta) is obtained. Thus the beam directional angle has no change even to a frequency change DELTAf an long as DELTAtheta=0 is satisfied. |
