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Prime Factor Frequency Multiplication Mechanism

IP.com Disclosure Number: IPCOM000082328D
Original Publication Date: 1974-Nov-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 4 page(s) / 68K

Publishing Venue

IBM

Related People

Caragliano, ES: AUTHOR [+2]

Abstract

Fig. 1A shows an arrangement whereby the frequency tripling of a base input frequency may be generated using only directional couplers, and a basic differential pair circuit. As can be seen in Fig. 1A, three directional couplers DC1, 2 and 3, each having an electrical length equal to 1/12 of the period of the base input frequency are distributed in tandem. The input to this coupler trio is fed by the periodic function A to be multiplied.

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Prime Factor Frequency Multiplication Mechanism

Fig. 1A shows an arrangement whereby the frequency tripling of a base input frequency may be generated using only directional couplers, and a basic differential pair circuit. As can be seen in Fig. 1A, three directional couplers DC1, 2 and 3, each having an electrical length equal to 1/12 of the period of the base input frequency are distributed in tandem. The input to this coupler trio is fed by the periodic function A to be multiplied.

The orientation of the couplers is such that the couplers 1 and 3 have the same orientation, whereas the middle coupler 2 is oppositely oriented. Note also that couplers 1 and 3 are properly terminated in their characteristic impedance, while the middle coupler 2 has one of its arms shorted to ground.

The output lines 10, 11 and 12 of the respective couplers 1, 2 and 3 are connected to the bases of respective transistors T1, T2 and T3 in the differential pair circuit. The tripled frequency is obtained at the collector of transistor T4 of the differential amplifier. A 2 tau delay mechanism 14 is connected in series with the output of coupler 3.

Fig. 1B shows five waveforms A through E corresponding to the points A - E of Fig. 1A. Waveform A is the incident periodic function. Waveform B is the resultant waveform produced by coupler 1 having a 1/12 electrical delay to that of the incoming frequency. Coupler 1 operates in the classical straightforward manner, wherein a pulse of 2 tau width is produced as a function of an incident step function. The polarity of this pulse being the same as the polarity associated with the polarity of the incident wave front referenced to ground. Therefore, as the incident wave front traverses through the main arm of coupler 1, the first part of waveform B is produced. The incident wave front now has traversed an electrical length = to 1 tau and enters the through arm of coupler 2.

As a result of the incident wave front passing through coupler 2, a pulse of 2 is produced in a standard backward manner which immediately reflects from the shorted coupled arm of coupler 2, producing a pulse of opposite phase to that initially coupled (waveform C). The reflected signal now proceeds to the base input of transistor T2 of the differential pair circuit, in a manner similar to the waveform B which was applied to the input of T1 of the differential pair circuit.

The incident wave front now enters the main arm of coupler 3, where a coupled pulse is produced similar to that which was produced from coupler 1 but delayed in time, as is shown in waveform D. An additional delay of 2 tau is associated with the coupled signal, due to the serial 2 tau delay mechanism 14 in series with the coupled arm of coupler 3. The delayed signal (waveform D) is applied to the base of...