US 3,944,937 AGranted

Broad-band signal transmitting device using transformer

AssigneeMatsushita Electric Industrial Co., Ltd.

InventorsSeiji Fujisawa, Toru Michioka

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Abstract

A broad-band signal transmitting device including a signal transmitting transformer of the primary to secondary turn ratio 1 : N, comprising a first circuit for expanding the transmission band to low frequencies by decreasing the impedance as well as by decreasing the gain for the signal component in the primary circuit of the transmission transformer, a second circuit connected with the output side of the transmission transformer having an impedance larger than N.sup.2 times of the impedance of the primary side and smaller than the impedance exhibited by the stray capacitance of the secondary side at the upper limit of the transmission band, an amplifier for recovering the gain drop in the first circuit, and a low frequency compensating circuit for compensating the lack of low frequency transmission characteristic due to the transmission transformer.

Claims9

Dependent claims

A broad-band signal transmitting device including a signal transmitting transformer of a primary-to-secondary turn ratio 1 :

N, comprising:
First circuit means for decreasing the gain of signal components applied to the input side of said transmission transformer and for expanding the transmission band of said transmission transformer to a lower frequency;
second circuit means connected with the output side of said transmission transformer and having an impedance sufficiently larger than N.sup.2 times of the characteristic impedance of the input side transmission line of said transmission transformer and smaller than the impedance exhibited by the stray capacitance existing between the output terminals of said transmission transformer at the higher limit of the transmission frequencies;
amplifying circuit means for receiving the signal gain which has been decreased by said first circuit means;
and
low frequency compensating circuit means for compensating the lack of low frequency transmission characteristic in said first circuit means and said signal transmitting transformer.

3 more elements

A broad-band signal transmitting device including a signal transmitting transformer having a primary-to-secondary turn ratio of 1 :

N an no common ground for the primary and the secondary windings, comprising:
First circuit means for reducing the gain for signal components applied to the primary side of said tranmission transformer and thereby expanding the transmission band of said transmission transformer to a lower frequency;
second circuit means connected between the secondary side terminals of said transmission transformer, having the middle point grounded, and having an impedance sufficiently larger than N.sup.2 times of the characteristic impedance of the primary side of said transmission transformer and smaller than the impedance exhibited by the stray capacitance existing between the secondary side terminals of said transmission transformer at the upper end of the transmission frequencies;
differential amplifier circuit means for differentially amplifying the signals from the both ends of said second circuit means;
and
low frequency compensating circuit means for compensating the lack in low frequency transmission characteristic of said first circuit means and said signal transmission transformer.

3 more elements

Dependencies are inferred from the claim text.