Broadband nonlinear drive control network for linear amplifiers arranged in several amplifier channels

• US 5,017,888 A
• Filed: 03/01/1990
• Issued: 05/21/1991
• Est. Priority Date: 03/01/1989
• Status: Expired due to Fees

• Current Assignee: Messerschmitt-Boelkow-Blohm GmbH (Mercedes-Benz Group AG)
• Original Assignee: Messerschmitt-Boelkow-Blohm GmbH (Mercedes-Benz Group AG)
• Inventors: Meinzer, Karl
• Primary Examiner(s): Mottola, Steven
• Application Number:
  US07/486,951
• Time in Patent Office: 446 Days
• Field of Search: 307/540, 330/84, 330/909, 330/124 D, 330/124 R, 330/284, 330/295, 330/302, 333/124
• US Class Current: 330/295
• CPC Class Codes: H03F 1/3276 using the nonlinearity inherent to components, e.g. a diode
• CPC Class Codes: H03F 1/56 Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602

Abstract

A broadband nonlinear drive control network for linear amplifiers with several amplifier channels has a first branch (Z1) with an adjustable amplitude limiter (A) connected to a signal source (S) through an impedance inverter (B), whereby an increasing impedance is produced at the signal source (S) when the limiter is activated. A variable resistor (C) is connected to the signal source (S) in a second branch (Z2). The resistor (C) begins to conduct only above an adjustable high frequency signal voltage. The amplitudes at the limiter (A) and at the resistor are tuned to each other so that the load impedance at the signal source (S) remains constant. Linear branch signal combinations provide the drive control voltages for the individual channels (K2 . . . Kn). A portion of the power output of the branch (Z1) directly drives the amplifier channel (K1).

Claims

1. A broadband nonlinear control network for driving linear amplifiers arranged in channels, comprising a plurality of network branches, a first branch comprising amplitude adjustable limiter means for limiting a drive signal amplitude, to an adjustable amplitude value which is free of any phase-frequency characteristic, impedance inverter means connecting said limiter means to a signal source, whereby a rising impedance is applied to said signal source when said limiter means is activated, a second branch comprising a constant load impedance and a resistor means connecting said constant load impedance to said signal source, said resistor means having a characteristic such that said resistor means becomes conductive above an adjustable high frequency threshold voltage, whereby said resistor means connects said signal source to said constant load impedance, and wherein an amplitude of a signal at said limiter means and an amplitude at said resistor means when said resistor means becomes conductive, are adjusted to each other so that a conductance, which has been reduced by an activation of said limiter means at said signal source, is compensated by a variable conductivity of the resistor means so that a load of said signal source remains constant, said first branch further comprising power divider means for branching off a portion of an output drive signal from said limiter means to drive a first channel of said amplifier channels, said control network further comprising hybrid circuit means connected to said first and second branches for producing further drive signals for further amplifier channels by a linear signal combination in said hybrid circuit means for performing a phase and amplitude correction, whereby said further drive signals have phase and amplitude characteristics required for said further amplifier channels.

2. The network of claim 1, wherein said amplitude adjustable limiter means comprise a reverse biased semiconductor diode having a characteristic with an adjustable activation point.

3. The network of claim 1, wherein said resistor means comprise a reverse biased semiconductor diode having a high frequency dependent conductivity, said constant load impedance and said reverse biased semiconductor diode being connected in series with each other.

4. The network of claim 1, wherein said first and second branches are connected in parallel with each other.