Connect public, paid and private patent data with Google Patents Public Datasets

Radio transmitting system

Download PDF

Info

Publication number
US2462181A
US2462181A US55611144A US2462181A US 2462181 A US2462181 A US 2462181A US 55611144 A US55611144 A US 55611144A US 2462181 A US2462181 A US 2462181A
Authority
US
Grant status
Grant
Patent type
Prior art keywords
frequency
crystal
wave
signals
connected
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Inventor
Walter H Grosselfinger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lucent Technologies Inc
Original Assignee
Lucent Technologies Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03CMODULATION
    • H03C3/00Angle modulation
    • H03C3/10Angle modulation by means of variable impedance

Description

Patented Feb. 22, 1949 RADIO TRANSMITTING SYSTEM Walter H. Grosselfinger, Manhasset, N. Y., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application September 28, 1944, Serial No. 556,111

1 Claim.

This invention relates to radio transmitting systems and, more particularly, to radio transmitting systems employing frequency modulation.

An object of the invetion is to, provide radio transmitting systems with improved frequency modulation circuits.

Another object is to provide for increased frequency modulation of piezoelectric; controlled oscillators.

It is also an object of the invention to provide radio transmitting systems with improved frequency modulation circuits for causing the frequency of radiated wave energy to be varied between two difierent values.

An additional object is to provide a frequency modulation circuit with improved means for increasing the range of the frequency changes produced during frequency modulation opera tions.

Another object is to provide radio transmitting systems with improved frequency modulation circuits for shifting the frequency of the radio carrier wave energy from one value to another in accordance with signals.

Another object is to provide a radio transmitting system with an improved electronic frequency shift keying circuit.

A further object 'is to improve the performance of keying circuits in radio telegraph transmitting systems by reducing keying transients.

These and other objects are attained by employing an improved electronic keying circuit for varying the frequency of wave energy generated by a high frequency thermionic oscillator. This keying circuit comprises a piezoelectric crystal connected in series with the grid of the oscillator for determining the frequency of the wave energy generated by the oscillator. An electronic switch, in the form of a double-diode rectifier, and a small capacitance are connected in series and are also connected in parallel across the crystal. When the double-diode rectifier is not conductive this circuit will be open with the result that the oscillator will generate wave energy of a particular frequency, such as the marking frequency. On. the other hand, when positive current is applied to the anodes of the double-diode rectifien as by the. action of a keying relay. the re inertube will. become. Qimductive. This, in e -est. clos s. the Parallel. cir u connec he condenser across the crystal thereby causing the frequency of the wave. energy generated by the thermionic oscillator to be reduced toa lower value; namely, the spacing frequency. An inductance is connected in series with the crystal and the grid of the oscillator for the, purpose of expanding the frequency change produced in keying so that there will be a relatively wide, frequency separation between the marking and spacing frequencies. A wave shaping filter, such as aresistance-capacitance network, is connected in the current supply circuit of the double-diode rectifier for effecting a more gradual slope in the conducting characteristic of this tube in order to reduce keying transients which would tend to be created if the condenser should be abruptly connected across the crystal. The principles of the invention are not limited solely to the transmission of telegraph signals but are also applicable to the transmission of audio frequency signals.

These and other features of the invention are more fully explained in connection with the following detailed description of the drawing, in which:

Fig. 1 illu-strates'a radio telegraph transmitting system provided with, a preferred form of the improved electronic frequency shift keying circuit;

Fig. 2 shows the invention applied to a voice frequency transmitting system{ and Fig. 3 shows the invention applied to a combined telegraph and voice frequency radio transmitting system.

In Fig. 1, a radio transmitting system is shown to be provided with a source of marking and spacing polar telegraph signals represented by a negative battery I, a positive battery 2, and a manually operable key 3. Operation of the key 3 alternatively connects batteries I and 2 to ground 4 through the winding of a polarized keying relay 5. Since relay 5 is polarized, it will operate its armature alternatively to its left and right contacts to connect either negative battery 6 or positive battery 1 to the anodes of a doublediode rectifier 8. This current supply circuit for the double-diode 8 contains a relatively large isolating resistance 9: and a wave shaping filter constituted by a resistance-capacitance network comprisinga resistance Ill and a capacitance H. Incidentally, it should be noted thatthe positive battery I is considerably larger than the, negative change during keying operations.

battery 6. A voltage regulator I 2 is connected to the positive battery I for maintaining a constant voltage supply for the double-diode 8.

The rectifier 8 constitutes an electronic switch for shifting the frequency of the wave energy generated by a high frequency thermionic oscillator I3 from the marking frequency to the spacing frequency and vice versa without changing the amplitude of this wave energy. Since the frequency of the waveenergy enerated by oscillator I3 is controlled by a piezoelectric crystal I4 connected to the grid of oscillator I3, the frequency shift is effected by causing the rectifier tube 8 to switch a small variable air condenser I5 in parallel with crystal I4 whenever it is desired to transmit wave energy having the spacing frequency.

In order to expand the frequency separation between the marking and spacing frequencies, a small inductance I5 is connected in the grid circult of oscillator I3 in series with crystal I4. It should be noted that the bridge circuit containing the double-diode 8 and the condenser I5 is connected across both the crystal I4 and the inductance I6. This permits the use of a larger capacity for condenser I5 than would otherwise be possible. Bymeans of this combination, it is possible to obtain a relatively wide frequency For example, in a preferred embodiment of the invention, the keying circuit produces a frequency separation of 850 cycles between the marking and spacing frequencies. The inductance I6 also increases the stability of the circuit and improves its operation, particularly when the condenser I5 is bridged across the crystal I4 and the inductance I 6.

The use of the electronic switch 8 instead of an electromagnetic relay for switching the condenser I5 across the crystal I4 and its associated inductance I6 reduces the occurrence of keying transients that might otherwise be produced by abruptly connecting condenser I5 across crystal I 4 and inductance I8. Keying transients are further reduced by means of the wave shaping filter, constituted by resistance In and capacitance I I, connected in the current supply circuit of the double-diode rectifier 8. This is due to the fact that the wave shaping filter effects a more gradual change in the conducting characteristic of the double-diode 8 thereby avoiding the creation of steep wave fronts.

In operating the system of Fig. 1, marking and spacing polar telegraph signals are originated by the operation of key 3. When a marking signal is to be transmitted, key 3 is operated to the position shown in Fig. 1 to connect negative current from battery I to the winding of the keying relay 5. This causes relay 5 to operate its armature to its marking contact thereby supplying negative current from battery 6 to the anodes of the double-diode 8 to prevent it from being conductive. The parallel circuit containing condenser I5 will now be open and the crystal controlled oscillator I3 will now produce wave energy having the marking frequency. This wave energy is amplified by an amplifier IT and is further amplified by a power amplifier I8 which has its outnut'connected to the transmitting antenna 20.

When it is desired to transmit a spacing signal, key 3 is operated to connect positive current from battery 2 to the winding of the keying relay 5. Relay 5 now operates its armature to its spacing contact to connect positive current from battery 2| battery I to the anodes of the double-diode 8. The rectifier 8 thus becomes conductive thereby connecting condenser I5 in parallel with crystal I4 and inductance I6. Thus causes the frequency of the wave energy produced by the crystal controlled oscillator I3 to be lowered to the spacing frequency. v

In some applications of the invention, it is desirable to be able to switch the marking and spacing frequencies quickly from one set of Values to another. This can be accomplished by employing two sets of the crystal-inductance-condenser combination with a switch for alternatively connecting either set into the keying circuit. Such a switch is constituted by the switching relay which is energized by current from whenever the manually operable switch 22 is closed. When switch 22 is open, as

is shown in Fig. 1, relay 20 is not energized and its top and bottom armatures are both in engagement with their outer contacts. Under this condition, the system will transmit wave energy having alternative marking and spacing frequency values which are determined by the crystal I I-inductance Iii-condenser I5 combination in the manner described above.

In order to transmit wave energy having different marking and spacing frequencies, a different crystal 24 and a different series connected inductance 26 are connected to the lower inner contact of relay 20 in the manner shown in Fig. 1 and a different small variable air condenser 25 is connected to the upper inner contact of relay 20. When the switch 22 is closed. current from battery 2 I will energize relay 20 which will move its top and bottom armatures into engagement with their inner contacts. This will switch the crystal I i-inductance Iii-condenser I5 combination out of the keying circuit and will connect the crystal 24-inductance ZB-condenser 25 combination into the keying circuit. The wave energy that will now be produced by oscillator I3 will have either a marking frequency determined by crystal 24 and inductance 26 or a spacing frequency determined by condenser 25, crystal 24, and inductance 26. Thus, by these means. the system shown in Fig. 1 can be switched readily from the transmission of wave energy having one set of marking and spacing frequencies to the transmission of wave energy having a different set of marking and spacing frequencies. It is to be understood that the invention is not limited to the specific source of telegraph signals shown in the drawing as various other means of supplying telegraph signals may be employed, such as a teletypewriter.

Fig. 2 illustrates the manner in which the invention is applied to an audio frequency radio transmitting system and shows a radio transmitting system somewhat similar to that shown in Fig. 1 but provided with a source 20!) of audio frequency signals of varying amplitude instead of a source of telegraph signals. The source 205 of audio frequency signals may be of any suitable design, such as a handset and its associated circuit for converting speech waves into electric waves of varying amplitude. Audio frequency signals from the source 200 are supp ied to the primary winding of a transformer 23]. Transformer 23I has its secondary winding connected in series with the current supply circuit of a double-diode rectifier 208 through an inductance and a potentiometer 235. This current supply circuit includes a positive battery 20'! and a voltage regulator 2l2. Rectifier tube 29 8; and a s mall 'variable air condenser M are, in turn, eenn et dgin parallel ith. a. cir en inins a crystal 2M connected in series with a small inductance 2H5. Crystal 2M and its series connected inductance 216' are connected to the grid of a frequency thermionjg oscillator-M3.

In operating the system shown in; Fig. 2, potentiometer fiitiisso adiustedthat, When there is an absence of'audio frequency signals, rectifier iiitvv llv be. partially conduct and wi l: be: ope

ating at a point approximately at the mid-point of its conducting characteristic. When audio frequency signals are present, they are superimposed upon that portion of the direct current from battery 20'! which passes over the potentiometer 235 and through the secondary winding of transformer 23L This causes a fluctuating direct current to be supplied to the anodes of the double-diode rectifier 238 so that it alternatively becomes moreconductive and less conductive in accordance with the variations in the amplitude of the audio frequency signals. Since the charge on condenser 2l5 varies in proportion to the conductivity of double-diode 208, the effect of placing condenser 3L5 in parallel with crystal 2M and inductance 2H5 will vary in accordance with the variations in the conductivity of the rectifier tube 208. In other words, the wave energy produced by the crystal controlled oscillator 2l3 will vary in frequency in a manner corresponding to the variations in the amplitude of the audio frequency signals. The wave energy from oscillator H3 is amplified by an amplifier 2|! and is also further amplified by a power amplifier 2I8. The output of power amplifier 218 is connected to a transmitting antenna 219 which radiates the frequency modulated wave energy into space for reception by a frequency modulation receiving system.

Fig. 3 illustrates the manner in which the invention is applied to a combined telegraph and voice frequency radio transmitting system for transmitting either telegraph signals or audio frequency signals. The circuit elements of the system shown in Fig. 3 are somewhatsimilar to those shown in Figs. 1 and 2 but include, in addition, a control switch 330. The operation of switch 33! which is shown in the form of a cradle switch, is controlled by the operation of the handset 300, which constitutes a source of audio frequency signals of variable amplitude. When the handset 300 is resting in its cradle 350, the cradle switch 330 will be open as shown in Fig. 3. When the handset 30!! is lifted out of its cradle 360, switch 330 will be closed.

If it is desired to transmit telegraph signals instead of speech signals, key 303 is operated between its contacts to connect either positive current from battery 302 or negative current from battery 3M to the winding of polarized relay 385. Since relay 335 is polarized, positive current in its winding will cause its armature to engage its spacing contact and negative current in its winding will actuate its armature into engagement with its marking contact thereby closing a circuit extending from a small negative battery 333 to potentiometer 335. Potentiometer 335 is connected in the grid circuit of a triode 308 and is so adjusted that triode 308 is normally operating at a point approximately at the mid-point of its conducting characteristic. If battery 333 is connected to the grid circuit of triode 308 by relay 305,1then triode 308 will cease to be conductive and condenser 31-5 will not be connected in parallel across crystal- 314 and its series connected inductance 3| 6. As a result, the crystal controlled oscillator 313 will produce wave energy having the marking frequency. If'battery 333 is not connected to the grid circuit of triode 338, as is the case when positive I 7 332.! is applied to the winding of relay 335' to actuate its armature into engagement with its pac contact, he. triode 3. .8 W be partially conductive to a sufficient extent to connect condenser 3l5'in parallel with crystal 3% and its series connected inductance 3l6. As was explained above in connection with the description of the operation of the system shown in Fig. 1, this will lower the frequency of the wave energy produced by the crystal controlled oscillator 3l3 to the spacing frequency.

On the other hand, if it is desired to transmit speech signals instead of telegraph signals, then the removal of the handset 333 from its cradle 360 will effect the closure of the control switch 333, as was described above, to connect negative current from battery 333 to potentiometer 335 thereby short-circuiting the path extending from battery 333 through the armature of relay 305. The audio frequency signals from the handset 333 are superimposed by transformer 33! upon the negative grid current from battery 333 and the resulting fluctuating direct current causes triode 3&8 to alternatively become more conductive and less conductive in accordance with the variations in the amplitude of the audio frequency signals. These variations in the conductivity of triode 338 will, as was explained above in connection with the description of the operation of the system shown in Fig. 2, cause the frequency of the wave energy now produced by the crystal controlled oscillator 353 to vary in a manner corresponding to the variations in the amplitude of the audio frequency signals.

What is claimed is:

A signal transmitting system comprising in combination a source of telegraph signals including a telegraph relay, a source of audio frequency signals including a telephone handset provided with a cradle switch, an electronic oscillator for generating high frequency electric wave energy,

a piezoelectric crystal for controlling said oscillator for determining the frequency of said wave energy, and modulating means for effecting changes in the frequency of said wave energy from one wavelength to a different wavelength in accordance with variations in said signals, said modulating means including a condenser and an electronic tube connected in series with each other and in parallel with the crystal, said electronic tube having a plurality of electrodes including a grid, a source of grid bias voltage for said tube, and control means for effecting changes in the conductivity of said tube in accordance with variations in said signals, said control means being characterized by having (References on following page) current from battery 7 REFERENCES CITED The following references are of record in the file of this patent:

STATES PATENTS Number Name Date Brackett Dec. 15, 1925 Trouand Apr. 3, 1934 Goddard Apr. 30, 1935 Fichandler May '7, 1935 Koerner Dec. 2, 1941 Number Number OTHER REFERENCES Termans Radio Engineers Handbook of 1943.

US2462181A 1944-09-28 1944-09-28 Radio transmitting system Expired - Lifetime US2462181A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US2462181A US2462181A (en) 1944-09-28 1944-09-28 Radio transmitting system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US2462181A US2462181A (en) 1944-09-28 1944-09-28 Radio transmitting system

Publications (1)

Publication Number Publication Date
US2462181A true US2462181A (en) 1949-02-22

Family

ID=24219936

Family Applications (1)

Application Number Title Priority Date Filing Date
US2462181A Expired - Lifetime US2462181A (en) 1944-09-28 1944-09-28 Radio transmitting system

Country Status (1)

Country Link
US (1) US2462181A (en)

Cited By (44)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2561989A (en) * 1949-08-02 1951-07-24 Tropical Radio Telegraph Compa Frequency modulator
US2636941A (en) * 1950-04-25 1953-04-28 Westinghouse Electric Corp Frequency shift keying circuits
US2731549A (en) * 1951-08-29 1956-01-17 Gen Railway Signal Co Radio communication system
US6049706A (en) * 1998-10-21 2000-04-11 Parkervision, Inc. Integrated frequency translation and selectivity
US6061551A (en) * 1998-10-21 2000-05-09 Parkervision, Inc. Method and system for down-converting electromagnetic signals
US6061555A (en) * 1998-10-21 2000-05-09 Parkervision, Inc. Method and system for ensuring reception of a communications signal
US6091940A (en) * 1998-10-21 2000-07-18 Parkervision, Inc. Method and system for frequency up-conversion
US20010027561A1 (en) * 1998-11-30 2001-10-04 Microsoft Corporation Video on demand methods and systems
US20010038318A1 (en) * 1999-11-24 2001-11-08 Parker Vision, Inc. Phased array antenna applications for universal frequency translation
US6370371B1 (en) 1998-10-21 2002-04-09 Parkervision, Inc. Applications of universal frequency translation
US20020042257A1 (en) * 2000-04-14 2002-04-11 Sorrells David F. Apparatus, system, and method for down-converting and up-converting electromagnetic signals
US20020049038A1 (en) * 2000-01-28 2002-04-25 Sorrells David F. Wireless and wired cable modem applications of universal frequency translation technology
US20020124036A1 (en) * 2000-11-14 2002-09-05 Parkervision, Inc. Method and apparatus for a parallel correlator and applications thereof
US20030022640A1 (en) * 1999-08-23 2003-01-30 Parker Vision, Inc. Method and system for frequency up-conversion
US6542722B1 (en) 1998-10-21 2003-04-01 Parkervision, Inc. Method and system for frequency up-conversion with variety of transmitter configurations
US6560301B1 (en) 1998-10-21 2003-05-06 Parkervision, Inc. Integrated frequency translation and selectivity with a variety of filter embodiments
US20030181189A1 (en) * 1999-04-16 2003-09-25 Sorrells David F. Method and apparatus for reducing DC offsets in communication systems using universal frequency translation technology
US20040015420A1 (en) * 2002-07-18 2004-01-22 Sorrells David F. Networking methods and systems
US20040013177A1 (en) * 2002-07-18 2004-01-22 Parker Vision, Inc. Networking methods and systems
US6694128B1 (en) 1998-08-18 2004-02-17 Parkervision, Inc. Frequency synthesizer using universal frequency translation technology
US6704549B1 (en) 1999-03-03 2004-03-09 Parkvision, Inc. Multi-mode, multi-band communication system
US6704558B1 (en) 1999-01-22 2004-03-09 Parkervision, Inc. Image-reject down-converter and embodiments thereof, such as the family radio service
US20040185901A1 (en) * 2003-03-18 2004-09-23 Tdk Corporation Electronic device for wireless communications and reflector device for wireless communication cards
US6813485B2 (en) 1998-10-21 2004-11-02 Parkervision, Inc. Method and system for down-converting and up-converting an electromagnetic signal, and transforms for same
US20040230628A1 (en) * 2000-11-14 2004-11-18 Rawlins Gregory S. Methods, systems, and computer program products for parallel correlation and applications thereof
US6873836B1 (en) 1999-03-03 2005-03-29 Parkervision, Inc. Universal platform module and methods and apparatuses relating thereto enabled by universal frequency translation technology
US20050100115A1 (en) * 1999-04-16 2005-05-12 Sorrells David F. Method, system, and apparatus for balanced frequency Up-conversion of a baseband signal
US20050123025A1 (en) * 1999-08-04 2005-06-09 Sorrells David F. Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments and circuit implementations
US20050136861A1 (en) * 1998-10-21 2005-06-23 Parkervision, Inc. Method and system for frequency up-conversion with modulation embodiments
US6963734B2 (en) 1999-12-22 2005-11-08 Parkervision, Inc. Differential frequency down-conversion using techniques of universal frequency translation technology
US6975848B2 (en) 2002-06-04 2005-12-13 Parkervision, Inc. Method and apparatus for DC offset removal in a radio frequency communication channel
US7006805B1 (en) 1999-01-22 2006-02-28 Parker Vision, Inc. Aliasing communication system with multi-mode and multi-band functionality and embodiments thereof, such as the family radio service
US7027786B1 (en) 1998-10-21 2006-04-11 Parkervision, Inc. Carrier and clock recovery using universal frequency translation
US7054296B1 (en) 1999-08-04 2006-05-30 Parkervision, Inc. Wireless local area network (WLAN) technology and applications including techniques of universal frequency translation
US7072427B2 (en) 2001-11-09 2006-07-04 Parkervision, Inc. Method and apparatus for reducing DC offsets in a communication system
US7085335B2 (en) 2001-11-09 2006-08-01 Parkervision, Inc. Method and apparatus for reducing DC offsets in a communication system
US7110435B1 (en) 1999-03-15 2006-09-19 Parkervision, Inc. Spread spectrum applications of universal frequency translation
US20070230611A1 (en) * 1999-04-16 2007-10-04 Parkervision, Inc. Apparatus and method of differential IQ frequency up-conversion
US7295826B1 (en) 1998-10-21 2007-11-13 Parkervision, Inc. Integrated frequency translation and selectivity with gain control functionality, and applications thereof
US7321640B2 (en) 2002-06-07 2008-01-22 Parkervision, Inc. Active polyphase inverter filter for quadrature signal generation
US7515896B1 (en) 1998-10-21 2009-04-07 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, and transforms for same, and aperture relationships
US7554508B2 (en) 2000-06-09 2009-06-30 Parker Vision, Inc. Phased array antenna applications on universal frequency translation
US7724845B2 (en) 1999-04-16 2010-05-25 Parkervision, Inc. Method and system for down-converting and electromagnetic signal, and transforms for same
US8295406B1 (en) 1999-08-04 2012-10-23 Parkervision, Inc. Universal platform module for a plurality of communication protocols

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1566245A (en) * 1921-09-02 1925-12-15 Westinghouse Electric & Mfg Co Radiotelephone system
GB314343A (en) * 1928-06-25 1930-07-17 Telefunken Gmbh Improvements in or relating to wireless signalling apparatus
US1953140A (en) * 1927-06-18 1934-04-03 Westinghouse Electric & Mfg Co Radio transmitting system
US1999656A (en) * 1932-03-14 1935-04-30 Rca Corp Oscillator circuits
US2000584A (en) * 1931-10-05 1935-05-07 Fichandler Carl Frequency control
US2264764A (en) * 1939-05-03 1941-12-02 Bell Telephone Labor Inc Crystal-controlled oscillator
US2274648A (en) * 1940-05-02 1942-03-03 Radio Patents Corp Variable electronic reactance
US2282102A (en) * 1940-12-12 1942-05-05 Rca Corp Signaling
US2291369A (en) * 1941-11-21 1942-07-28 Western Union Telegraph Co Polar carrier telegraph system
US2392625A (en) * 1943-09-09 1946-01-08 Rca Corp Signaling system

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1566245A (en) * 1921-09-02 1925-12-15 Westinghouse Electric & Mfg Co Radiotelephone system
US1953140A (en) * 1927-06-18 1934-04-03 Westinghouse Electric & Mfg Co Radio transmitting system
GB314343A (en) * 1928-06-25 1930-07-17 Telefunken Gmbh Improvements in or relating to wireless signalling apparatus
US2000584A (en) * 1931-10-05 1935-05-07 Fichandler Carl Frequency control
US1999656A (en) * 1932-03-14 1935-04-30 Rca Corp Oscillator circuits
US2264764A (en) * 1939-05-03 1941-12-02 Bell Telephone Labor Inc Crystal-controlled oscillator
US2274648A (en) * 1940-05-02 1942-03-03 Radio Patents Corp Variable electronic reactance
US2282102A (en) * 1940-12-12 1942-05-05 Rca Corp Signaling
US2291369A (en) * 1941-11-21 1942-07-28 Western Union Telegraph Co Polar carrier telegraph system
US2392625A (en) * 1943-09-09 1946-01-08 Rca Corp Signaling system

Cited By (148)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2561989A (en) * 1949-08-02 1951-07-24 Tropical Radio Telegraph Compa Frequency modulator
US2636941A (en) * 1950-04-25 1953-04-28 Westinghouse Electric Corp Frequency shift keying circuits
US2731549A (en) * 1951-08-29 1956-01-17 Gen Railway Signal Co Radio communication system
US6694128B1 (en) 1998-08-18 2004-02-17 Parkervision, Inc. Frequency synthesizer using universal frequency translation technology
US7050508B2 (en) 1998-10-21 2006-05-23 Parkervision, Inc. Method and system for frequency up-conversion with a variety of transmitter configurations
US6061555A (en) * 1998-10-21 2000-05-09 Parkervision, Inc. Method and system for ensuring reception of a communications signal
US6091940A (en) * 1998-10-21 2000-07-18 Parkervision, Inc. Method and system for frequency up-conversion
US6266518B1 (en) 1998-10-21 2001-07-24 Parkervision, Inc. Method and system for down-converting electromagnetic signals by sampling and integrating over apertures
US8340618B2 (en) 1998-10-21 2012-12-25 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, and transforms for same, and aperture relationships
US8233855B2 (en) 1998-10-21 2012-07-31 Parkervision, Inc. Up-conversion based on gated information signal
US6353735B1 (en) 1998-10-21 2002-03-05 Parkervision, Inc. MDG method for output signal generation
US6370371B1 (en) 1998-10-21 2002-04-09 Parkervision, Inc. Applications of universal frequency translation
US8190116B2 (en) 1998-10-21 2012-05-29 Parker Vision, Inc. Methods and systems for down-converting a signal using a complementary transistor structure
US8190108B2 (en) 1998-10-21 2012-05-29 Parkervision, Inc. Method and system for frequency up-conversion
US6421534B1 (en) 1998-10-21 2002-07-16 Parkervision, Inc. Integrated frequency translation and selectivity
US8160534B2 (en) 1998-10-21 2012-04-17 Parkervision, Inc. Applications of universal frequency translation
US20020160809A1 (en) * 1998-10-21 2002-10-31 Parker Vision, Inc. Applications of universal frequency translation
US8019291B2 (en) 1998-10-21 2011-09-13 Parkervision, Inc. Method and system for frequency down-conversion and frequency up-conversion
US6061551A (en) * 1998-10-21 2000-05-09 Parkervision, Inc. Method and system for down-converting electromagnetic signals
US20030068990A1 (en) * 1998-10-21 2003-04-10 Parkervision, Inc. Method and system for frequency up-conversion with a variety of transmitter configurations
US6560301B1 (en) 1998-10-21 2003-05-06 Parkervision, Inc. Integrated frequency translation and selectivity with a variety of filter embodiments
US6580902B1 (en) 1998-10-21 2003-06-17 Parkervision, Inc. Frequency translation using optimized switch structures
US20030112895A1 (en) * 1998-10-21 2003-06-19 Parkervision, Inc. Intergrated frequency translation and selectivity
US6049706A (en) * 1998-10-21 2000-04-11 Parkervision, Inc. Integrated frequency translation and selectivity
US20030186670A1 (en) * 1998-10-21 2003-10-02 Sorrells David F. Method and circuit or down-converting a signal
US6647250B1 (en) 1998-10-21 2003-11-11 Parkervision, Inc. Method and system for ensuring reception of a communications signal
US20110151821A1 (en) * 1998-10-21 2011-06-23 Parkervision, Inc. Methods and Systems for Down-Converting a Signal Using a Complementary Transistor Structure
US7937059B2 (en) 1998-10-21 2011-05-03 Parkervision, Inc. Converting an electromagnetic signal via sub-sampling
US7936022B2 (en) 1998-10-21 2011-05-03 Parkervision, Inc. Method and circuit for down-converting a signal
US6687493B1 (en) 1998-10-21 2004-02-03 Parkervision, Inc. Method and circuit for down-converting a signal using a complementary FET structure for improved dynamic range
US20110183640A1 (en) * 1998-10-21 2011-07-28 Parkervision, Inc. Method and System for Down-Converting an Electromagnetic Signal, and Transforms for Same, and Aperture Relationships
US7865177B2 (en) 1998-10-21 2011-01-04 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, and transforms for same, and aperture relationships
US7826817B2 (en) 1998-10-21 2010-11-02 Parker Vision, Inc. Applications of universal frequency translation
US7697916B2 (en) 1998-10-21 2010-04-13 Parkervision, Inc. Applications of universal frequency translation
US6798351B1 (en) 1998-10-21 2004-09-28 Parkervision, Inc. Automated meter reader applications of universal frequency translation
US6813485B2 (en) 1998-10-21 2004-11-02 Parkervision, Inc. Method and system for down-converting and up-converting an electromagnetic signal, and transforms for same
US20100056084A1 (en) * 1998-10-21 2010-03-04 Parkervision, Inc. Frequency Conversion Based on Gated Information Signal
US6836650B2 (en) 1998-10-21 2004-12-28 Parkervision, Inc. Methods and systems for down-converting electromagnetic signals, and applications thereof
US20050009494A1 (en) * 1998-10-21 2005-01-13 Parkervision, Inc. Method and system for down-converting and up-converting an electromagnetic signal, and transforms for same
US7620378B2 (en) 1998-10-21 2009-11-17 Parkervision, Inc. Method and system for frequency up-conversion with modulation embodiments
US20090221257A1 (en) * 1998-10-21 2009-09-03 Parkervision, Inc. Method and System For Down-Converting An Electromagnetic Signal, And Transforms For Same, And Aperture Relationships
US20090181627A1 (en) * 1998-10-21 2009-07-16 Parkervision, Inc. Applications of Universal Frequency Translation
US7529522B2 (en) 1998-10-21 2009-05-05 Parkervision, Inc. Apparatus and method for communicating an input signal in polar representation
US7515896B1 (en) 1998-10-21 2009-04-07 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, and transforms for same, and aperture relationships
US7376410B2 (en) 1998-10-21 2008-05-20 Parkervision, Inc. Methods and systems for down-converting a signal using a complementary transistor structure
US20050136861A1 (en) * 1998-10-21 2005-06-23 Parkervision, Inc. Method and system for frequency up-conversion with modulation embodiments
US7321735B1 (en) 1998-10-21 2008-01-22 Parkervision, Inc. Optical down-converter using universal frequency translation technology
US7308242B2 (en) 1998-10-21 2007-12-11 Parkervision, Inc. Method and system for down-converting and up-converting an electromagnetic signal, and transforms for same
US20050202797A1 (en) * 1998-10-21 2005-09-15 Sorrells David F. Methods and systems for down-converting electromagnetic signals, and applications thereof
US20050215207A1 (en) * 1998-10-21 2005-09-29 Parkervision, Inc. Method and system for frequency up-conversion with a variety of transmitter configurations
US7295826B1 (en) 1998-10-21 2007-11-13 Parkervision, Inc. Integrated frequency translation and selectivity with gain control functionality, and applications thereof
US20070259627A1 (en) * 1998-10-21 2007-11-08 Parkervision, Inc. Method and system for frequency up-conversion with modulation embodiments
US20050272395A1 (en) * 1998-10-21 2005-12-08 Parkervision, Inc. Method and circuit for down-converting a signal
US7245886B2 (en) 1998-10-21 2007-07-17 Parkervision, Inc. Method and system for frequency up-conversion with modulation embodiments
US7389100B2 (en) 1998-10-21 2008-06-17 Parkervision, Inc. Method and circuit for down-converting a signal
US7194246B2 (en) 1998-10-21 2007-03-20 Parkervision, Inc. Methods and systems for down-converting a signal using a complementary transistor structure
US7218907B2 (en) 1998-10-21 2007-05-15 Parkervision, Inc. Method and circuit for down-converting a signal
US7016663B2 (en) 1998-10-21 2006-03-21 Parkervision, Inc. Applications of universal frequency translation
US7027786B1 (en) 1998-10-21 2006-04-11 Parkervision, Inc. Carrier and clock recovery using universal frequency translation
US7076011B2 (en) 1998-10-21 2006-07-11 Parkervision, Inc. Integrated frequency translation and selectivity
US7039372B1 (en) 1998-10-21 2006-05-02 Parkervision, Inc. Method and system for frequency up-conversion with modulation embodiments
US6542722B1 (en) 1998-10-21 2003-04-01 Parkervision, Inc. Method and system for frequency up-conversion with variety of transmitter configurations
US7693502B2 (en) 1998-10-21 2010-04-06 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, transforms for same, and aperture relationships
US20010027561A1 (en) * 1998-11-30 2001-10-04 Microsoft Corporation Video on demand methods and systems
US6704558B1 (en) 1999-01-22 2004-03-09 Parkervision, Inc. Image-reject down-converter and embodiments thereof, such as the family radio service
US7006805B1 (en) 1999-01-22 2006-02-28 Parker Vision, Inc. Aliasing communication system with multi-mode and multi-band functionality and embodiments thereof, such as the family radio service
US20050164670A1 (en) * 1999-03-03 2005-07-28 Parkervision, Inc. Universal platform module and methods and apparatuses relating thereto enabled by universal frequency translation technology
US6873836B1 (en) 1999-03-03 2005-03-29 Parkervision, Inc. Universal platform module and methods and apparatuses relating thereto enabled by universal frequency translation technology
US7483686B2 (en) 1999-03-03 2009-01-27 Parkervision, Inc. Universal platform module and methods and apparatuses relating thereto enabled by universal frequency translation technology
US6704549B1 (en) 1999-03-03 2004-03-09 Parkvision, Inc. Multi-mode, multi-band communication system
US7599421B2 (en) 1999-03-15 2009-10-06 Parkervision, Inc. Spread spectrum applications of universal frequency translation
US7110435B1 (en) 1999-03-15 2006-09-19 Parkervision, Inc. Spread spectrum applications of universal frequency translation
US7272164B2 (en) 1999-04-16 2007-09-18 Parkervision, Inc. Reducing DC offsets using spectral spreading
US8223898B2 (en) 1999-04-16 2012-07-17 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, and transforms for same
US7773688B2 (en) 1999-04-16 2010-08-10 Parkervision, Inc. Method, system, and apparatus for balanced frequency up-conversion, including circuitry to directly couple the outputs of multiple transistors
US7224749B2 (en) 1999-04-16 2007-05-29 Parkervision, Inc. Method and apparatus for reducing re-radiation using techniques of universal frequency translation technology
US8224281B2 (en) 1999-04-16 2012-07-17 Parkervision, Inc. Down-conversion of an electromagnetic signal with feedback control
US20100260289A1 (en) * 1999-04-16 2010-10-14 Parkervision, Inc. Method, System, and Apparatus for Balanced Frequency Up-Conversion of a Baseband Signal
US20100111150A1 (en) * 1999-04-16 2010-05-06 Parkervision, Inc. Wireless Local Area Network (WLAN) Using Universal Frequency Translation Technology Including Multi-Phase Embodiments
US8229023B2 (en) 1999-04-16 2012-07-24 Parkervision, Inc. Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments
US20110092177A1 (en) * 1999-04-16 2011-04-21 Parkervision, Inc. Down-Conversion of an Electromagnetic Signal with Feedback Control
US20070230611A1 (en) * 1999-04-16 2007-10-04 Parkervision, Inc. Apparatus and method of differential IQ frequency up-conversion
US7539474B2 (en) 1999-04-16 2009-05-26 Parkervision, Inc. DC offset, re-radiation, and I/Q solutions using universal frequency translation technology
US7190941B2 (en) 1999-04-16 2007-03-13 Parkervision, Inc. Method and apparatus for reducing DC offsets in communication systems using universal frequency translation technology
US8077797B2 (en) 1999-04-16 2011-12-13 Parkervision, Inc. Method, system, and apparatus for balanced frequency up-conversion of a baseband signal
US8036304B2 (en) 1999-04-16 2011-10-11 Parkervision, Inc. Apparatus and method of differential IQ frequency up-conversion
US8594228B2 (en) 1999-04-16 2013-11-26 Parkervision, Inc. Apparatus and method of differential IQ frequency up-conversion
US7724845B2 (en) 1999-04-16 2010-05-25 Parkervision, Inc. Method and system for down-converting and electromagnetic signal, and transforms for same
US20050100115A1 (en) * 1999-04-16 2005-05-12 Sorrells David F. Method, system, and apparatus for balanced frequency Up-conversion of a baseband signal
US20100303178A1 (en) * 1999-04-16 2010-12-02 Parkervision, Inc. Method and System for Down-Converting an Electromagnetic Signal, and Transforms for Same
US20030181189A1 (en) * 1999-04-16 2003-09-25 Sorrells David F. Method and apparatus for reducing DC offsets in communication systems using universal frequency translation technology
US20040002321A1 (en) * 1999-04-16 2004-01-01 Parker Vision, Inc. Method and apparatus for reducing re-radiation using techniques of universal frequency translation technology
US20060083329A1 (en) * 1999-04-16 2006-04-20 Parkervision Inc. Methods and systems for utilizing universal frequency translators for phase and/or frequency detection
US7929638B2 (en) 1999-04-16 2011-04-19 Parkervision, Inc. Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments
US7894789B2 (en) 1999-04-16 2011-02-22 Parkervision, Inc. Down-conversion of an electromagnetic signal with feedback control
US6879817B1 (en) 1999-04-16 2005-04-12 Parkervision, Inc. DC offset, re-radiation, and I/Q solutions using universal frequency translation technology
US7693230B2 (en) 1999-04-16 2010-04-06 Parkervision, Inc. Apparatus and method of differential IQ frequency up-conversion
US7110444B1 (en) 1999-08-04 2006-09-19 Parkervision, Inc. Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments and circuit implementations
US7653145B2 (en) 1999-08-04 2010-01-26 Parkervision, Inc. Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments and circuit implementations
US20050123025A1 (en) * 1999-08-04 2005-06-09 Sorrells David F. Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments and circuit implementations
US8295406B1 (en) 1999-08-04 2012-10-23 Parkervision, Inc. Universal platform module for a plurality of communication protocols
US7054296B1 (en) 1999-08-04 2006-05-30 Parkervision, Inc. Wireless local area network (WLAN) technology and applications including techniques of universal frequency translation
US7546096B2 (en) 1999-08-23 2009-06-09 Parkervision, Inc. Frequency up-conversion using a harmonic generation and extraction module
US7236754B2 (en) 1999-08-23 2007-06-26 Parkervision, Inc. Method and system for frequency up-conversion
US20030022640A1 (en) * 1999-08-23 2003-01-30 Parker Vision, Inc. Method and system for frequency up-conversion
US20070224950A1 (en) * 1999-08-23 2007-09-27 Parkervision, Inc. Method and system for frequency up-conversion
US20010038318A1 (en) * 1999-11-24 2001-11-08 Parker Vision, Inc. Phased array antenna applications for universal frequency translation
US7379515B2 (en) 1999-11-24 2008-05-27 Parkervision, Inc. Phased array antenna applications of universal frequency translation
US7082171B1 (en) 1999-11-24 2006-07-25 Parkervision, Inc. Phase shifting applications of universal frequency translation
US6963734B2 (en) 1999-12-22 2005-11-08 Parkervision, Inc. Differential frequency down-conversion using techniques of universal frequency translation technology
US20020049038A1 (en) * 2000-01-28 2002-04-25 Sorrells David F. Wireless and wired cable modem applications of universal frequency translation technology
US7292835B2 (en) 2000-01-28 2007-11-06 Parkervision, Inc. Wireless and wired cable modem applications of universal frequency translation technology
US7218899B2 (en) 2000-04-14 2007-05-15 Parkervision, Inc. Apparatus, system, and method for up-converting electromagnetic signals
US8295800B2 (en) 2000-04-14 2012-10-23 Parkervision, Inc. Apparatus and method for down-converting electromagnetic signals by controlled charging and discharging of a capacitor
US7107028B2 (en) 2000-04-14 2006-09-12 Parkervision, Inc. Apparatus, system, and method for up converting electromagnetic signals
US20050227639A1 (en) * 2000-04-14 2005-10-13 Parkervision, Inc. Apparatus, system, and method for down converting and up converting electromagnetic signals
US7010286B2 (en) 2000-04-14 2006-03-07 Parkervision, Inc. Apparatus, system, and method for down-converting and up-converting electromagnetic signals
US20050085208A1 (en) * 2000-04-14 2005-04-21 Parkervision, Inc. Apparatus, system, and method for down-converting and up-converting electromagnetic signals
US7386292B2 (en) 2000-04-14 2008-06-10 Parkervision, Inc. Apparatus, system, and method for down-converting and up-converting electromagnetic signals
US7822401B2 (en) 2000-04-14 2010-10-26 Parkervision, Inc. Apparatus and method for down-converting electromagnetic signals by controlled charging and discharging of a capacitor
US20050085207A1 (en) * 2000-04-14 2005-04-21 Parkervision, Inc. Apparatus, system, and method for down-converting and up-converting electromagnetic signals
US7496342B2 (en) 2000-04-14 2009-02-24 Parkervision, Inc. Down-converting electromagnetic signals, including controlled discharge of capacitors
US20020042257A1 (en) * 2000-04-14 2002-04-11 Sorrells David F. Apparatus, system, and method for down-converting and up-converting electromagnetic signals
US7554508B2 (en) 2000-06-09 2009-06-30 Parker Vision, Inc. Phased array antenna applications on universal frequency translation
US7454453B2 (en) 2000-11-14 2008-11-18 Parkervision, Inc. Methods, systems, and computer program products for parallel correlation and applications thereof
US7433910B2 (en) 2000-11-14 2008-10-07 Parkervision, Inc. Method and apparatus for the parallel correlator and applications thereof
US7010559B2 (en) 2000-11-14 2006-03-07 Parkervision, Inc. Method and apparatus for a parallel correlator and applications thereof
US7233969B2 (en) 2000-11-14 2007-06-19 Parkervision, Inc. Method and apparatus for a parallel correlator and applications thereof
US20020124036A1 (en) * 2000-11-14 2002-09-05 Parkervision, Inc. Method and apparatus for a parallel correlator and applications thereof
US20080294708A1 (en) * 2000-11-14 2008-11-27 Parkervision, Inc. Methods, systems, and computer program products for parallel correlation and applications thereof
US20050193049A1 (en) * 2000-11-14 2005-09-01 Parkervision, Inc. Method and apparatus for a parallel correlator and applications thereof
US7991815B2 (en) 2000-11-14 2011-08-02 Parkervision, Inc. Methods, systems, and computer program products for parallel correlation and applications thereof
US20040230628A1 (en) * 2000-11-14 2004-11-18 Rawlins Gregory S. Methods, systems, and computer program products for parallel correlation and applications thereof
US8446994B2 (en) 2001-11-09 2013-05-21 Parkervision, Inc. Gain control in a communication channel
US7072427B2 (en) 2001-11-09 2006-07-04 Parkervision, Inc. Method and apparatus for reducing DC offsets in a communication system
US20100086086A1 (en) * 2001-11-09 2010-04-08 Parkervision, Inc. Gain control in a communication channel
US20070086548A1 (en) * 2001-11-09 2007-04-19 Parkervision, Inc. Method and apparatus for reducing DC offsets in a communication system
US7085335B2 (en) 2001-11-09 2006-08-01 Parkervision, Inc. Method and apparatus for reducing DC offsets in a communication system
US7653158B2 (en) 2001-11-09 2010-01-26 Parkervision, Inc. Gain control in a communication channel
US6975848B2 (en) 2002-06-04 2005-12-13 Parkervision, Inc. Method and apparatus for DC offset removal in a radio frequency communication channel
US7321640B2 (en) 2002-06-07 2008-01-22 Parkervision, Inc. Active polyphase inverter filter for quadrature signal generation
US7460584B2 (en) 2002-07-18 2008-12-02 Parkervision, Inc. Networking methods and systems
US20040013177A1 (en) * 2002-07-18 2004-01-22 Parker Vision, Inc. Networking methods and systems
US8160196B2 (en) 2002-07-18 2012-04-17 Parkervision, Inc. Networking methods and systems
US20040015420A1 (en) * 2002-07-18 2004-01-22 Sorrells David F. Networking methods and systems
US8407061B2 (en) 2002-07-18 2013-03-26 Parkervision, Inc. Networking methods and systems
US7379883B2 (en) 2002-07-18 2008-05-27 Parkervision, Inc. Networking methods and systems
US20040185901A1 (en) * 2003-03-18 2004-09-23 Tdk Corporation Electronic device for wireless communications and reflector device for wireless communication cards

Similar Documents

Publication Publication Date Title
US2514679A (en) Wave transmission
US2570939A (en) Semiconductor reactance circuit
US2189317A (en) Diversity antenna system
US2524782A (en) Selective calling system
US2461456A (en) Frequency shift keying
US2379395A (en) Fm transceiver
US2855508A (en) Dual frequency resonant circuits
US2147595A (en) Ultra high frequency transceiver
US2425316A (en) Pulse repeater system
US2282405A (en) Transmission system
US3458657A (en) Remote control over power lines by transmitting high frequency pulses in phase with positive and negative half cycles of the power line current
US2307771A (en) Carrier current communication system
US2930991A (en) Frequency shift oscillator
US2527561A (en) Selective calling system
US2295323A (en) Current limiting device
US2461646A (en) Carrier-wave communication system
US2385673A (en) Carrier current system
US2326314A (en) Frequency modulation
US2834879A (en) Frequency selective system
US1705993A (en) Voltage-limiting device
US3283074A (en) Voice-controlled communication system
US2018569A (en) Radio signaling apparatus
US2967992A (en) Signal expansion device
US2427850A (en) Switching method and system
US2245347A (en) Radio remote control system