| 摘要 |
PURPOSE:To obtain the 4-element antenna unit high in the operation gain and small size and light weight, by using the element having negative reactance with very small loss and the positive reactance control circuit canceling the negative reactance. CONSTITUTION:Two pairs of dipole antennas 31, 32 and 33, 34 opposing each other are located orthogonally, and each antenna is constituted with elements 15, 15' having broad surface area and having distributed inductance of small loss. Further, these elements are connected with the resonant circuit consisting of the coil 16, variable capacitor 17, capacitor 18, coil 16', variable capacitor 17' and capacitor 18' to cancel the reactive component of the elements to each frequency. Further, the antenna unit is provided with the switching control means 43, 44 to control the directivity in four ways. Thus, the four-element antenna unit high in the operation gain, small in size and light in weight can be obtained. |
