Home | Links | Contact Us | More About Intellectual Property | Bookmark

Search patents:

Home

Coded

Image-reject-apparatus-for-signal-synthesis-applications

Crystalline silicophosphoaluminate MCM-1

What is claimed is: 1. A synthetic crystalline material having a composition as follows: vA:M.sup.m+...

Video tape recorder having status display mode

What is claimed is: 1. A video recording and/or reproducing system which facilitates rapid ...

Marking and counting probe assembly

Briefly, the apparatus employed to practice the invention generally comprises a novel probe ...

Circuit arrangement for a video recorder

What is claimed is: 1. A circuit for processing a chrominance signal in a video recorder comprising:...

Data processing circuit for calculating either a total sum or a total product of a series of data at a high speed

What is claimed is: 1. A data processing circuit for use in a scalar machine in combination with ...

Test apparatus for defects of plate

What is claimed is: 1. A test apparatus for defects on a plate comprising: first surface ...

Digital pulse detector circuit having selectable false alarm rate

A method and apparatus is disclosed for detecting a repeated pulse in an input signal in which the ...

Noise generator with shaped spectrum

The invention is the first self-filtering pseudorandom noise generator. This is accomplished by ...

Noise immune data regenerating circuit for video signal reproduction

According to a broader aspect of the invention, a data regenerating circuit is provided for video ...

Device for detecting the exceeding of a temperature threshold

In order to obtain this result the invention provides a device for detecting the exceeding of a ...

Image reject apparatus for signal synthesis applications

Details

Inventors: Mower, Vaughn L.;
Assignee: Unisys Corporation (Blue Bell, PA)
Primary Examiner: LaRoche; Eugene R.
Assistant Examiner: Pascal; Robert J.
Attorney, Agent or Firm: Sowell; John B., Peterson; Kevin K., Scott; Thomas J.

An image reject apparatus for covering a broad range of signal systhesis frequencies is provided with a digital phase shifter having an input for receiving modulated signals at twice the desired output frequency. A modulator comprising a power divider having a radio frequency (RF) input, a pair of mixers coupled to the outputs of said digital phase shifter and to the outputs from said power divider provides mixer output signals which are combined to produce sum and difference product signals as desired side band signals.

DETAILED DESCRIPTION It is a principal object of the present invention to provide an improved image reject circuit which is capable of being used in fixed frequency square wave frequency synthesis applications.
It is another principal object of the present invention to provide a frequency synthesized image reject circuit which is particularly suited as an input to a phase-locked loop which locks onto the selected image signal and which filters out undesirable modulation frequency harmonics.
It is another principal object of the present invention to provide a novel digital phase shifter which is coupled to a novel modulator whose input frequency is twice the desired modulated side band frequency.
It is a general object of the present invention to provide a novel image reject circuit which mixes a low frequency digital input square wave signal with a much higher radio frequency signal.
It is a general object of the present invention to provide a novel image reject circuit which eliminates analog phase-shifters in the modulating signal circuit.
It is a general object of the present invention to provide a novel image reject circuit having a novel digital phase shifting circuit which is operable over a very broad range of frequencies and limited only by the speed of the devices employed in the digital circuits.
It is a general object of the present invention to provide a novel image reject circuit which has a negligible phase degradation versus modulation frequency.
It is an object of the present invention to provide a novel image reject circuit having bandwidth ratios in excess of 200 to 1 and is particularly suited for eliminating linear phase distortions versus frequency.
According to these and other objects of the present invention there is provided a digital phase shifter having an input for receiving modulated signals (2FM) at twice the desired the output sideband frequency.
A modulator comprising a power divider having an RF frequency (F.
sub.
RF), a pair of mixer coupled to the output of said digital phase shifter and to the outputs from said power divider to provide mixer output signals which are combined to produce sum and difference signals at the desired side band frequencies (F

Related patents

	Method and apparatus for protection of skin against mosquitos and other insects I have endeavored to devise a practical and economical way to elevate an insect excluding fabric away from the wearer's skin that accommodates those areas were fabric ...
	Removable lamp housing for optical encoder OF THE PREFERRED EMBODIMENT Referring first to the lower portion of FIG. 1, there is shown the upper portion of a motor casing 10 having an output shaft 11 for the ...
	Moving target radar The prior art as taught by the Kalmus articles includes a mechanically operating correlator which may be an eddy-current drag disc or relatively movable coils operating ...
	Gain-controlled amplifier circuits What I claim is: 1. A gain-controlled amplifier circuit which includes a pair of gain-controlled amplifiers, signal generating means operable to generate a pilot signal ...
	Method and apparatus utilizing time-expanded pulse sequences for distance measurement in a radar We claim: 1. A method of processing radar echo pulse sequences having steep pulse flanks and a predetermined sequence frequency, comprising the steps of: generating an ...
	Coordinate converter for changing polar vector variable into Cartesian vector variables According to the invention, this problem is solved by means of a first and a second multiplier in conjunction with an adder and a subtractor, the first variable being ...
	Tape guide assemblies for video cassettes I claim: 1. In a video tape cassette comprising a housing; a predetermined length of magnetic recording tape; first and second reels rotatably mounted in said housing, ...
	Transmitting antenna employing radial fins What I claim as new and desire to secure by Letters Patent is: 1. An antenna assembly for transmitting signals of a given wavelength comprising: a. an electrically ...
	Radar system for detecting approaching vehicles from behind An object of the present invention is therefore to provide a radar system which ensures safety against possible collision of carelessly opened doors of a stationary ...
	Process for partial removing of impurities from a wet process phosphoric acid Wet process phosphoric acid is produced by decomposing natural phosphate rock with sulfuric acid and filtering off the precipitated calcium sulfate. Depending upon the ...

0.134
Archive: All patents - Links Copyright (c)2006 Eipa-patents.org - All rights reserved