GB1292614A - Wide band amplifier - Google Patents

Abstract

1292614 Amplifiers; repeaters PYE Ltd 26 Nov 1969 [25 March 1969] 15559/69 Headings H3T and H4R [Also in Division H1] A wide band amplifier arrangement has a feedback resistor R1 connected between the output and input terminals of an amplifying stage A1, these terminals and the resistor R1 are connected to input and output striplines 1, 2 and the input and output impedances of the stage A1 are substantially equal to the characteristic impedance of the striplines 1, 2. In the common emitter amplifier stages A1, A2 shown and matched as above negative voltage feed back is provided by resistors R1, R4 and R2, R7. The characteristic impedance of the striplines 1, 2, 3 is chosen to substantially equal the characteristic impedance of connecting lines (L1, L2, Fig. 1, not shown) such as coaxial cables or twin line feeder connected to sockets S 1 , S 2 . The stripline sections 1, 2, 3 may be formed on a printed circuit board (5, Fig. 3, not shown) including a large conductive area 4 for earth on one side of the board, a positive supply rail (6) and the sections 1, 2 on the other side of the board and with the resistor R1 between the conductor sections 1 and 2. The transistor Tr1 of the amplifier stage A1 may be mounted in a cut out at the edge of the board (5). As an alternative the arrangement may be in the form of a film circuit in which the conductive areas 1, 2, 4 are deposited on an insulating substrate, e.g. by silk screen printing using a conductive ink and the resistors are then formed as film resistors, e.g. by using a resistive ink. Valve amplifying circuits may be used. The amplifier arrangement is suitable for repeater amplifiers for use in multi channel carrier telephony systems or in television signal distribution networks.