Frequency measuring means

Claim 2

A frequency measuring means comprising a network having input means for receiving an input signal which is to have its frequency measured and output means delivering signals transmitted therethrough, said network providing a signal transfer characteristic which is a function of frequency for the range of frequencies to be measured, first means deriving from the input means of said network only input signals reflected by said network, second means deriving from the output means of said network only input signals transmitted by said network, and third means receiving and comparing signals from said first and second means for providing an indication of the frequency of a signal delivered to the input of said network.

Claim 3

The frequency measuring means of claim 1 in which said network comprises an electrical filter with a continuous cut-off characteristic which is a function of frequency for the range of frequencies to be measured.

Claim 4

The frequency measuring means of claim 2 in which said filter network is a low pass filter.

Claim 5

The frequency measuring means of claim 2 in which said filter network is of the Butterworth type.

Claim 6

The frequency measuring means of claim 1 in which said third means includes first and second signal amplitude detectors respectively receiving reflected signals from the first means and transmitted signals from said second means and delivering respective output signals, first and second amplifiers receiving detected signals respectively from said first and second detectors and delivering respective output signals which are logarithmic functions of the received signals, and a comparator receiving the output signals from said first and second amplifiers and delivering output signals which correspond to the difference between the received signals for providing an indication of the frequency of the signal delivered to the input of said network.

Claim 7

A frequency measuring means comprising a network having input means for receiving a signal which is to have its frequency measured and output means delivering signals transmitted therethrough, said network providing a signal transfer characteristic which is a function of frequency for the range of frequencies to be measured, first means deriving signals reflected from the input means of said network, Second means deriving from the output means signals transmitte by said network, and thrid means receiving and comparing signals from said first and second means for providing an indication of the frequency of a signal delivered to the input of said network, said first means including a first coupling unit having an input for receiving a signal which is to have its frequency measured, an output delivering input signals to the input means of said network and an another output delivering signals reflected from the input means of said network, said second means including a second coupling unit having an input for receiving output signals from the output means of said network and an output delivering signals received from said network.

Claim 8

A frequency measuring means comprising a network having input means for receiving a signal which is to have its frequency measured and output means delivering signals transmitted therethrough, said network providing a signal transfer characteristic which is a function of frequency for the range of frequencies to be measured, first means deriving signals reflected from the input means of said network, Second means deriving from the output means signals transmitte by said network, and thrid means receiving and comparing signals from said first and second means for providing an indication of the frequency of a signal delivered to the input of said network, said first means including a first coupling unit having an input for receiving a signal which is to have its frequency measured, an output delivering input signals to the input means of said network and an another output delivering signals reflected from the input means of said network, said second means including a second coupling unit having an input for receiving output signals from the output means of said network and an output delivering signals received from said network.

Claim 9

The frequency measuring means of claim 6 in which said network includes first and second electrical filters each having an input and an output and a continuous cut-off characteristic which is a function of frequency for the range of frequencies to be measured, said first coupling unit has first and second output terminals delivering an input signal to the respective inputs of the first and second filters and a third output terminal delivering signals reflected from the inputs of said first and second filters, and said second coupling unit has first and second input terminals receiving input signals respectively from the outputs of said first and second filters and a third output terminal delivering signals received from the outputs of said filters.

Claim 10

A frequency measuring means comprising a network having input means for receiving a signal which is to have its frequency measured and output means delivering signals transmitted threrthrough, said network providing a signal transfer characteristic which is a function of frequency for the range of frequencies to be measured, first means deriving signals reflected from the input means of said network, second means deriving from the output means signals transmitted by said network, and third means receiving and comparing signals from said first and second means for providing an indication of the frequency of a signal delivered to the input of said network, said third means including first and second signal amplitude detectors respectively receiving reflected signals from the first means and transmitted signals from said second means and delivering respective output signals, first and second amplifiers receiving detected signals respectively from said first and second detectors and delivering respective output signals which are logarithmic functions of the received signals, and a comparator receiving the output signals from said first and second amplifiers and delivering output signals which correspond to the difference between the received signals for providing an indication of the frequency of the signal delivered to the input of said network, said network including first and second electrical filters each having an input and an output and a continuous cut-off characteristic which is a function of frequency for the range of frequencies to be measured, said first means including a first coupling unit having an input terminal for receiving a signal which is to have its frequency measured, first and second output terminals each delivering an input signal to the respective inputs of the first and second filters and a third output terminal delivering to the first detector of said third means signals reflected from the inputs of said first and second filters, and said second means including a second coupling unit having first and second input terminals receiving input signals respectively from the outputs of said first and second filters and a third output terminal delivering to the second detector of said third means signals received from the outputs of said filters.

Claim 11

A frequency measuring means comprising a network having input means for receiving a signal which is to have its frequency measured and output means delivering signals transmitted threrthrough, said network providing a signal transfer characteristic which is a function of frequency for the range of frequencies to be measured, first means deriving signals reflected from the input means of said network, second means deriving from the output means signals transmitted by said network, and third means receiving and comparing signals from said first and second means for providing an indication of the frequency of a signal delivered to the input of said network, said third means including first and second signal amplitude detectors respectively receiving reflected signals from the first means and transmitted signals from said second means and delivering respective output signals, first and second amplifiers receiving detected signals respectively from said first and second detectors and delivering respective output signals which are logarithmic functions of the received signals, and a comparator receiving the output signals from said first and second amplifiers and delivering output signals which correspond to the difference between the received signals for providing an indication of the frequency of the signal delivered to the input of said network, said network including first and second electrical filters each having an input and an output and a continuous cut-off characteristic which is a function of frequency for the range of frequencies to be measured, said first means including a first coupling unit having an input terminal for receiving a signal which is to have its frequency measured, first and second output terminals each delivering an input signal to the respective inputs of the first and second filters and a third output terminal delivering to the first detector of said third means signals reflected from the inputs of said first and second filters, and said second means including a second coupling unit having first and second input terminals receiving input signals respectively from the outputs of said first and second filters and a third output terminal delivering to the second detector of said third means signals received from the outputs of said filters.

Claim 12

The frequency measuring means of claim 12 in which said first and second filters are identical and of the Butterworth type, said first and second coupling units are each of the 3 db quadrature hybrid type, said first and second detecTors are square-law diode detectors, and said comparator is a signal subtractor device.

Claim 13

The frequency measuring means of claim 12 including a frequency indicating means receiving the output signal from said comparator including converting means providing an output signal which relates to the antilog of the received signal and means response to the signal from said convertor for providing the frequency of the input signal to said network.