Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
148 words
In a logarithmic amplifier comprising a series of MESFET distributed amplifiers connected in cascade, each of said MESFET distributed amplifiers having a gate transmission line a drain transmission line a common ground line, a plurality of MESFETs connected in parallel, gate electrodes of said MESFET being connected at spaced intervals along said gate transmission line, drain electrodes of said MESFETs being connected at spaced intervals along said drain transmission line and source electrodes of said MESFETs being connected to said ground line; the improvement wherein said logarithmic amplifier also includes low pass filter means operatively connected to said gate transmission line of each distributed amplifier, said low pass filter means passing only a rectified component of said travelling wave passing along each gate transmission line, and summer means connected to said low pass filter means to provide an output, said summer providing an output of said logarithmic amplifier.
Claim 2
Dependent Claim
148 words
In a logarithmic amplifier comprising a series of MESFET distributed amplifiers connected in cascade, each of said MESFET distributed amplifiers having a gate transmission line a drain transmission line a common ground line, a plurality of MESFETs connected in parallel, gate electrodes of said MESFET being connected at spaced intervals along said gate transmission line, drain electrodes of said MESFETs being connected at spaced intervals along said drain transmission line and source electrodes of said MESFETs being connected to said ground line; the improvement wherein said logarithmic amplifier also includes low pass filter means operatively connected to said gate transmission line of each distributed amplifier, said low pass filter means passing only a rectified component of said travelling wave passing along each gate transmission line, and summer means connected to said low pass filter means to provide an output, said summer providing an output of said logarithmic amplifier.
Claim 3
Dependent Claim
62 words
The logarithmic amplifier of claim 1, also including impedance matching loads connected to ends of each gate transmission line wherein said gate transmission line of each said distributed amplifier includes decoupling capacitors operatively connected between said transmission line and said impedance matching loads and, wherein said low pass filter means is connected to said gate transmission lines immediately before said decoupling capacitor.
Claim 4
Dependent Claim
42 words
The logarithmic amplifier of claim 1, wherein each said low pass filter means is formed by a circuit to pass only a low frequency component corresponding to an amplitude modulation and d.c. component of a signal carried by each gate transmission line.
Claim 5
Dependent Claim
31 words
The logarithmic amplifier of claim 1, wherein said summer means is formed by a multi-input operational amplifier having outputs from each of said low pass filter means connected to its inputs.
Claim 6
Dependent Claim
19 words
The logarithmic amplifier of claim 1, wherein each of said distributed amplifiers connected in cascade includes four GaAs MESFETS.
Claim 7
Dependent Claim
17 words
The logarithmic amplifier of claim 5, wherein eight of said distributed amplifiers are connected together in cascade.
Claim 8
Dependent Claim
12 words
The logarithmic amplifier of claim 1, wherein said MESFETs are GaAs MESFETs.
Claim 9
Dependent Claim
28 words
The logarithmic amplifier of claim 1, wherein said distributed amplifiers are capable of handling microwave signals having a frequency in a range from 20 MHz to 50 GHz.