RADIO REPEATING AMPLIFIER

摘要

PURPOSE:To reduce the size and the cost of a radio repeating amplifier for blind zone which is used in a mobile telephone system of an operating frequency band including the inhibited frequency bands in both up and down circuits. CONSTITUTION:Filter parts 5 and 6 contain the BPF 53/54 and 63/64 of characteristics Fd and FD which can transmit the bands fa and f1 set at both sides of an inhibited band fA. Then both parts 5 and 6 are connected to a down circuit through the positions between the antenna sharing units 1 and 2 and a down amplifier 3. Meanwhile the filter parts 7 and 8 which contain the BPF 73/74 and 83/84 having the characteristics Fe and FE equal to the characteristics Fd and FD are connected to an UP circuit. As a result, the relative band width of the BPF is reduced and the sufficient mutual attenuation is secured between the up and down circuits. Therefore even an inexpensive BPF of the small degree suffices.