PERFEZIONAMENTO IN UN CIRCUITO AMPLIFICATORE A RADIOFREQUENZA, INTEGRATO, MONOLITICO, INCORPORANTE UN CONDENSATORE INTEGRATO.

Description

TITLE INV. DES. PRIORITY ITT INDUSTRIES INC. NEW YORK NYUSA IMPROVEMENT IN AN INTEGRATED, MONOLITHIC, EMBEDDING RADIO FREQUENCY AMPLIFIER CIRCUIT AN INTEGRATED CAPACITOR. FREYBERGER LAURIN CLEMENS FEDERAL REPUBLIC OF GERMANY PATENT DOCUMENT NO. P 29 27 934.3 OF 11 JULY 1979, Rome, 25 JUNE 1986 -'ν. ι tr ι ι pi lira ! Register A Protocol No. 1'3334 a / t'O MINISTRY OF INDUSTRY, COMMERCE AND CRAFTS Provincial Office of Industry, Commerce and Crafts of Milan COPY OF THE MINUTES OF FILING FOR INDUSTRIAL INVENTION PATENT In the year 1, on the ninth day of the month at the hours and minutes ITT INDUSTRIES, INC. of US nationality in New York, 10022 New York Via 320 Park Avenue, through the agent INDUSTRIE FACE STANDARD SPA and with domicile for legal purposes in Milan - Viale L. Bodio, 33 at the agent's office, has presented to me, the undersigned: PRINCIPAL - Stamped application for the granting of a patent for an industrial invention 'WiOW' entitled: IMPROVEMENT IN AN INTEGRATED, MONOLITHIC, RADIO FREQUENCY AMPLIFIER CIRCUIT INCORPORATING AN INTEGRATED CAPACITOR li, formerly designated: Laurin Clemens FREYBERGER Priority of patent application in: Federal Rep. of Germany No. P 29 27 934.3 of 11 July 1979 supplementary to patent no. (application no. dep. the granted accompanied by: - Description in duplicate of 7 pages of writing. - Drawings, plates η. 1 in duplo. - - Declaration referring to Power of Attorney. - Priority document and Italian translation - Authorization tfóffKPIOMiAftittfe. (ri Serva). - Declaration of consent of the inventor to be mentioned in the patent. - Proof of payment on postal account no. Q06680Q4 in the name of the Tax and Concession Registry Office Rome of L. 50. Issued by the Post Office of Milan 39 on 8.7.1980 n. 958 - Revenue stamp of L. 2,000, The application, descriptions and drawings listed above have been signed by the applicant and countersigned by me and stamped with the office stamp THE DEPOSITOR For a copy compliant with the original p. the Director (Salvatore Ravaili) THE HEAD OF THE BREVEHI OFFICE -------------------002 / pms) Τι'·'''.....R Ο ; f- / -a To the Ministry of Industry, Trade & Crafts Central Patent Office - Rome, Italy: ITT INDUSTRIES, INC., a United States corporation, with. 334 V ·?· V 1 » registered office at 320 Park Avenue, New York, 10022 NY (USA)J~~ through the Agent Industrie FACE Standard Sp A., with se» U n« QAMILANO f., -·. - · Ϊ?I y BR?vr·T '-n? 92333¼ O. .dein.....via Luigi Bodio 33,............Milan, where the Agent elects his legal domicile ___________DOMA........N D.......A........................................ the granting of a patent for an industrial invention for 1 year by title: IMPROVEMENT IN AN AMPLIFIER CIRCUIT.....AT RADIO FREQUENCY, INTEGRATED, MQ NOLITICO, INCORPORATING AN INTEGRATED CAPACITOR .................................................................................................... . , . . 'Designated inventor: Laurin Clemens FREYBERGER The Priority Right is claimed from a previous application No. P. .29..27.934. 3.......filed on 11 July 1979, in the Federal Republic of Germany. the po cumeniazione. attached: THE· Description in duplicate.......of 7 pages of writing; Reference Declaration to Power of Attorney; Priority Document with Translation; Authorization (reservation); Declaration of consent of the inventor to be mentioned in the Patent; 1 ' Τ'................................................................. t Industrio FACE STANDARD SpA LC Freyberger ·? 7 Description of the industrial invention entitled: IMPROVEMENT IN AN INTEGRATED, MONOLITHIC, RADIO FREQUENCY AMPLIFIER CIRCUIT INCORPORATING AN INTEGRATED CAPACITOR”. of the company: ITT INDUSTRIES Ine. a: New York NY (USA) Designated Inventor: Laurin Clemens FREYBERGER filed on JULY 1980 .ι n» 23 334 A / 80 SUMMARY OF THE INVENTION In a monolithic integrated RF amplifier circuit having a feedback branch, the improvement consisting of providing two transistor structures which are complementary to the amplifying transistors and are themselves used in a differential amplifier configuration and have their collectors intercoupled for maintaining the correct phase relationship with respect to the DC voltage, so that said transistors function as integrated capacitors for suppressing oscillations at frequencies above the transition frequency of said transistor structures and further, so that said transistor structures function as active components in said feedback branch. FACE STANDARD SpA Industries DESCRIPTION OF THE INVENTION Bipolar integrated circuits, that is, both their semiconductor structure and their circuit technology, are described, for example, in the journal Scientia electricia, 1963, pages 67–91. While the active components, that is, the transistor structures, diode structures, and resistors, are relatively easy to integrate, some problems arise when integrating capacitors. According to pages 81 and 83 of the aforementioned reference, these problems are essentially due to the fact that, for economic reasons, that is, lack of space, only capacitors of the order of about 1 nF can be realized. To date, therefore, capacitors of a higher value are not integrated but are connected via external terminals of the integrated circuit.This, however, requires at least one external terminal if one terminal of the capacitor is grounded or connected to the supply voltage, or even two external terminals if the capacitor is inserted between two circuit points not normally connected externally. In special applications, attempts have been made to overcome this difficulty by developing specific circuits that require lower capacitances than known circuits, so that integrated capacitors can be used. The purpose of the invention is to demonstrate another method of realizing capacitive effects in integrated circuits. According to the invention, this objective is achieved by using a bipolar transistor structure as an integrated capacitor at frequencies higher than the transition frequencies of the transistor structure. According to one aspect of the invention, pnp transistor structures FACE STANDARD S.pX side industries are particularly suitable for this purpose. A preferred application consists of a monolithic integrated RF amplifier in which the bipolar transistor structure is used both as a suppressor capacitor and as an active component in the feedback branch. The invention will now be explained in greater detail with reference to the accompanying drawing, the sole figure of which illustrates a preferred embodiment of the invention. The figure shows a balanced RF amplifier built on the principle of the differential amplifier. Its cutoff frequency is of the order of one gigahertz, in the present case about 1.5 GHz. A feedback branch from the output to the amplifier input is used to stabilize the DC operating point in the known manner. In the present case, according to the invention, the feedback branch contains two transistor structures operated in the active region and having a transition frequency lower than the amplifier cutoff frequency; preferably, the transition frequency is lower than the lowest operating frequency of the amplifier. As can be seen, the RF amplifier shown in the figure has three stages 1,2,3 of differential amplifiers. The first stage 1 contains the transistors T11, T12, its collector resistors R13, R14, the common emitter resistor R10 and the two input capacitors C1, C2 fed on the base of the transistors T11, T12, respectively. The second stage 2 contains the transistors T21, T22, its collector resistors R23, R24, the common emitter resistor R20 and the two stages of FACE STANDARD SpA Industries level shift formed by transistors T25, T26 and resistors R25, R26, respectively. This second stage is followed by emitter follower transistors T23, T24, whose emitter resistors are formed by the collector resistors R13, R14 of the first stage 1. The circuitry of a semi-shunt of the two differential stages e2 is presented in particular as follows: for simplicity, only a semi-shunt having an odd number in its reference numbers is described (left part of the figure): The collector of transistor TU is connected to the base of transistor T21 and to resistor R13. The collector of transistor T21 is connected to the base of transistor T23 and to resistor R23, the other terminal of which is on the emitter of transistor T25. Resistor R25 is connected in parallel to the base-collector path of transistor T25, the collector of which is connected to the supply voltage +UB filtered by the RC circuit. The base of transistor T23 is connected to the junction of resistor R23 and to the collector of transistor T21.The collector of transistor T23 is on the filtered supply voltage +UB and its emitter is connected to the terminal of resistor R13 which is not connected to the base of transistor T21. The third amplifier stage 3 contains the transistors T31, T32, the common emitter resistor R30 and the two collector resistors R31, R32 connected, with their terminals not touching the collectors, to the filtered supply voltage +UB. The base of transistor T31 is connected to the junction of resistor 4 Industrie FACE STANDARD S.pA re 13 and the emitter of transistor T23. In the figure, all the transistors of the three stages 1,3,2 mentioned above are npn transistors. The above-mentioned feedback is provided via the two transistor structures T1, T2, which are complementary to the amplifying transistors and, in turn, are used in a differential amplifier configuration, that is, their two emitters are connected to the filtered supply voltage UB via the resistor RI. The bases of the two transistor structures T1, T2 are connected to the collectors of transistors T31, T32 of the third amplifier stage 3. The collectors are cross-coupled (since the phase relationship must be maintained in an amplifier with respect to the DC voltage) to the bases of the amplifying transistors T1, T12 of the first amplifier stage 1.To fix the DC operating points of the two transistor structures T1, T2, resistors R11, R21 are connected between the collectors and ground and resistors R12, R22 are inserted between the collector of the respective transistor structure T2, T1 and the associated base of the respective transistor TU, T12 of the first amplifier stage 1. For emphasis, in the figure, the components and interconnecting wires belonging to the transistor structures T1, T2, used as integrated capacitors according to the invention, are drawn more markedly than the other components and interconnecting wires. The transistor structures Tl, T2 act as integrated capacitors, particularly for suppressing oscillations, at frequencies higher than the transition frequency of the transistor structures Tl, T2. In addition, they also act as active components in the feedback branch. FACE STANDARD S.p.A. Industries

Claims

1. CLAIMS 1 In a monolithic integrated radiofrequency amplifier circuit having a feedback leg, the improvement comprising: - providing two transistor structures which are complementary to the amplifier transistors and are in turn used in a differential amplifier configuration and have the inter-coupled collectors for maintaining the correct phase relationship with respect to the direct voltage, so that said transistors function as integrated capacitors for the suppression of oscillations at frequencies higher than the transition frequency of said transistor structures and moreover, so that said transistor structures work as active components in said counter-reaction branch. 2 - Integrated capacitor comprising: transistor means in an integrated circuit for providing an electronic response equivalent to that of a capacitor when the frequency of the circuit is above the transition frequency of the transistor means.

3. Integrated capacitor according to claim 2 wherein said transistor means is a bipolar transistor.

4. Integrated capacitor according to claim 2 wherein said transistor means is a lateral pnp transistor. Industrie FACE STANDARD S.pA 5 - Monolithic integrated radiofrequency amplifier in which: transistor means function both as an oscillation suppressor capacitor at a frequency above the transition frequency, and as an active component in a feedback branch. pp II authorized representative Industrie FACE STANDARD S.p.A. The attorney to sign Industrie FAC> STANDARD S.pA 03640 - L, C, Freyberger 7 (002 / pms) ATT © DI DESIGNATONE DELL'lNM ENTOR fi In the name and on behalf of the Company: ITT INDUSTRIES, INC. based at: 320 Park Avenue - New York, 10022 - New York anal holder of the patent application titled: IMPROVEMENT IN AN INTEGRATED, MONOLITHIC RADIO FREQUENCY AMPLIFIER CIRCUIT, INCORPORATING AN INTEGRATED DENSER * claiming the priority of the patent application in : (Rep. Fed, of G ermania No. P 29 27 934. 3 - of 11 July 1979, the undersigned Agent announces that the Messrs. Laurin Clemens FREYBERGER have been designated as inventors. The Agent: Industrie FACE Standard SpA. signature: Milan,