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Method and apparatus for alias-driven frequency downconversion (mixing)

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Publication number
WO1996002977A1
WO1996002977A1 PCT/US1995/008233 US9508233W WO1996002977A1 WO 1996002977 A1 WO1996002977 A1 WO 1996002977A1 US 9508233 W US9508233 W US 9508233W WO 1996002977 A1 WO1996002977 A1 WO 1996002977A1
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WO
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Application
Patent type
Prior art keywords
frequency
fig
hold
signal
oscillator
Prior art date
Application number
PCT/US1995/008233
Other languages
French (fr)
Inventor
Thomas Land
Original Assignee
Stanford Telecommunications, 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

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Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/0003Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain
    • H04B1/0007Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
    • H04B1/0017Digital filtering
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03DDEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D7/00Transference of modulation from one carrier to another, e.g. frequency-changing
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/0003Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/0003Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain
    • H04B1/0007Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
    • H04B1/001Channel filtering, i.e. selecting a frequency channel within the SDR system
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/0003Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain
    • H04B1/0007Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
    • H04B1/0025Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage using a sampling rate lower than twice the highest frequency component of the sampled signal
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06Receivers
    • H04B1/16Circuits
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06Receivers
    • H04B1/16Circuits
    • H04B1/26Circuits for superheterodyne receivers
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03BGENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B19/00Generation of oscillations by non-regenerative frequency multiplication or division of a signal from a separate source
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03BGENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B2200/00Indexing scheme relating to details of oscillators covered by H03B
    • H03B2200/006Functional aspects of oscillators
    • H03B2200/0082Lowering the supply voltage and saving power
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03BGENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B2200/00Indexing scheme relating to details of oscillators covered by H03B
    • H03B2200/006Functional aspects of oscillators
    • H03B2200/0088Reduction of noise
    • H03B2200/009Reduction of phase noise
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03BGENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B28/00Generation of oscillations by methods not covered by groups H03B5/00 - H03B27/00, including modification of the waveform to produce sinusoidal oscillations
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03DDEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D2200/00Indexing scheme relating to details of demodulation or transference of modulation from one carrier to another covered by H03D
    • H03D2200/0041Functional aspects of demodulators
    • H03D2200/005Analog to digital conversion
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03DDEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D2200/00Indexing scheme relating to details of demodulation or transference of modulation from one carrier to another covered by H03D
    • H03D2200/0041Functional aspects of demodulators
    • H03D2200/006Signal sampling

Abstract

Frequency conversion is achieved in a receiver by using sample and hold (44), and track and hold for circuits in place of conventional mixers. The invention enhances spectral power efficiency usig the alias-driven frequency translation techniques and is applicable to cover IF ranges from DC to 1 GHz (with sub-Hertz resolution).

Description

METHOD AND APPARATUS FOR ALIAS-DRIVEN FREQUENCY DOWNCONVERSION (MIXING) BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION:

The technique in which alternating electrical currents of different frequencies are mixed so that they modulate each other and produce, in the output components, frequencies equal to the sum and difference of the original frequencies, is called heterodyning and is traditionally achieved using a device most commonly referred to as a mixer. In modern communication systems, the mixer is a fundamental element present in many system designs. Although implementation of a traditional mixer may take one of several forms, a common feature of all traditional mixer implementations is the reliance on excitation of the mixer by a local oscillator (an alternating current source) of some fundamental frequency, f^, to achieve frequency translation of another signal by an amount equal in magnitude to

Traditional frequency translation methods rely upon local oscillator frequencies equivalent to the magnitude of frequency translation desired. When using conventional mixers, it is necessary that the local oscillator frequency be equal to the magnitude of frequency translation desired. Typically, as these local oscillator frequencies become higher, circuit complexity, behavior, and electrical power consumption increase. This is especially true in oscillator implementations supporting a broad frequency tuning range and having requirements for fine frequency tuning resolution, precision, and accuracy.

An object of the invention is to provide frequency downconversion apparatus and method which has a broad IF tuning range, enhanced spectral efficiency, and which simplifies local oscillator requirements; a further object of the invention is to provide frequency downconversion using sample-and-hold and track- and-hold circuits which have wide tuning range, low component- content and higher reliability.

The present invention provides apparatus and methods of RF frequency translation which may be termed Alias-Driven Frequency Downconversion. The invention can be implemented in part or in its entirety in analog signal-, digital signal-, and combined analog/digital signal-processing systems and is most effective when applied in translating a signal to lower frequencies (downconversion) more efficiently than existing techniques using conventional mixer technologies.

The ability to perform frequency translation of bandwidth- limited signals by integer multiples of the local oscillator frequency f^ and with greater spectral power efficiency results in substantial savings in design and implementation complexity, power consumption, size, and cost with simultaneous enhancement to performance and reliability may be realized over implementations based upon traditional methods of frequency translation.

Briefly described, in place of the conventional mixer used for downconversion in RF receivers, the present invention adapts electronic sample-and-hold and electronic track-and-hold circuits to achieve frequency translation to a lower frequency (downconversion) .

The invention is applicable to IF ranges from DC to 1 GHz (with sub-Hertz) resolution) using currently available technology and with substantially no circuit modification. The same broad input bandwidth in a conventionally designed system requires a very complex and broad range frequency synthesizer whose complexity is certain to scale upwards as the range of octaves covered by the synthesizer is increased.

BRIEF DESCRIPTION OF THE DRAWINGS:

The above and other objects, advantages and features of the invention will become more apparent when considered with the following specification and accompanying drawings wherein:

FIG. la is a block diagram illustrating an example of a conventional high-resolution, precision variable frequency translation method using a conventional mixer;

FIG. lb is a block diagram illustrating a variable frequency translation method using spurious frequencies output and filtered from a digitally synthesized sinusoidal oscillator and using a conventional mixer;

FIG. 2a is a block diagram of an ideal electronic sample- and-hold apparatus;

FIG. 2b illustrates the time-domain action of the ideal electronic sample-and-hold apparatus; FIG. 2c is an illustration of the components of the frequency-domain transfer function for an ideal electronic sample-and-hold apparatus;

FIG. 3a is a block diagram of an ideal track-and-hold apparatus;

FIG. 3b illustrates the time-domain action of the ideal electronic track-and-hold apparatus;

FIG. 3c is an illustration of the frequency-domain transfer function components of an ideal electronic track-and-hold apparatus;

FIG. 4a is a block diagram illustrating frequency translation to a lower frequency (downconversion) utilizing the Alias-Driven Frequency Translation method as implemented in an apparatus using an electronic sample-and-hold device;

FIG. 4b graphically analyzes the single-sided frequency- domain donwconversion of the apparatus described in Fig. 4a;

FIG. 5a is a block diagram illustrating frequency translation to a lower frequency (downconversion) utilizing the Alias-Drive Frequency Translation method as implemented in an apparatus using an electronic track-and-hold device;

FIG. 5b graphically analyzes the single-sided frequency- domain downconversion of the apparatus described in Fig. 5a;

FIG. 6a illustrates an architecture and apparatus for Alias- Driven Frequency Downconversion utilizing an electronic sample- and-hold apparatus; FIGS. 6b through 6g graphically analyze in the time domain and frequency domain the signal, fin, as it progresses through the system presented in Fig. 6a at the three test points labeled TP4 through TP6;

FIGS. 7a and 7b compare the spectral power efficiency of frequency downconversion approaches using the ideal conventional mixer implementation of Fig. la or lb and of the Alias-Driven Frequency Translation implementation using an electronic sample- and-hold apparatus as illustrated in Fig. 6a;

FIG. 8a illustrates an architecture and apparatus for Alias- Driven Frequency Downconversion utilizing an electronic track- and-hold apparatus;

FIG. 8b through 8g graphically analyze in the time domain and frequency domain the signal, fln, as it progresses through the system presented in Fig. 8a at the three test points labeled TP7 through TP9;

FIG. 9 compares the spectral power efficiency of frequency donwconversion approaches using the ideal conventional mixer implementation of Fig. la or lb and of the Alias-Driven Frequency Translation implementation using an electronic track-and-hold apparatus as illustrated in Fig. 8a.

DETAILED DESCRIPTION OF THE INVENTION:

Referring to Fig. la, a conventional high resolution, precision variable frequency translation method is disclosed wherein the input FIF signal is applied through an image reject filter 10 to a conventional mixer 11. A frequency control word FHC0 is applied along with the clock frequency FCIJ- to a number controlled oscillator (NCO) 12, the output of which is converted to an analog signal in digital-to-analog converter 13, low pass filtered by low pass filter (LPF) 14 and supplied as the signal from the numerically controlled oscillator FHCo to a conventional mixer 15. A fixed frequency oscillator 16 supplies a second input to mixer 15 and the output is filtered by bandpass filter 17 so that the output FHC0 + FLO J-s applied as a second input to mixer 11. The output from mixer 11 is passed through bandpass filter 18 as the downconverted signal FIF - (FNC0 + FLO)*

Fig. lb is a block diagram illustrating a variable frequency translation method using spurious frequency outputs and filtered from a digitally synthesized sinusoidal oscillator and using a conventional mixer. In this system the signal from the numerically controlled oscillator 12' is converted to an analog signal in a high performance digital/analog converter 13' and the signal is filtered in bandpass filter 17' and the resulting output FCLK +/- FNC0 is supplied through a high frequency amplifier 19 and applied as a second input to the conventional mixer 11'.

Fig. 2a is a block diagram illustrating an ideal electronic sample and hold apparatus wherein the analog input signal VN (see Fig. 2b) is applied through an amplifier 20 which has a gain of 1 to electronic sampler switch 21 which is operated by an impulse generator 22 having a sample timing clock FCLK (see Fig. 2b, top line). The sampled pulses from switch 21 are stored in a storage device, such as capacitor 22 and provided as an analog output through amplifier 23 which has a gain of 1. Fig. 2c (line 1) is a simplified diagram of the ideal electronic sample and hold apparatus shown in Fig. 2a. Fig. 2c (line 2) illustrates an ideal sampler transfer function for the sampler shown in Fig. 2c, (line 1). Fig. 2c (line 3) illustrates a zero-order hold transfer function for the circuit shown in Fig. 2c (line 1).

Fig. 3a is a block diagram of an ideal track-and-hold circuit in which an analog input signal V1N is amplified by amplifier 30 (which has a gain of 1) and output is sampled by electronic sampling switch 31, which receives track/hold switch control signals from source 32. The output is stored on charge storage capacitor 33, passed through amplifier 34. Fig. 3b (line 1) shows the track (complement) and hold time intervals "T" and "H" which have a time period T8. Fig. 3b (line 2) shows the time domain action of the track-and-hold apparatus of Fig. 3a. The input analog signal V1H is shown as a sinusoidal wave (light trace) and the analog output Vouτ (heavy trace) tracks the input signal during the track periods (T) and holds the last value during the hold periods (H). Thus, at 35-1 the output trades the portion of the sine wave during track period Ti and holds the last valve 35-2 during period H2. During track period Tz the signal tracks the sine wave at 35-3 and holds the last value 35- 4, etc.

Fig. 3c (line 1) illustrates the frequency domain transfer function components of an electronic track-and-hold circuit and lines 2-4 illustrate the sampler transfer function (line 2), the hold transfer function (line 3) when TH _< T3 and the track transfer function (line 4) when Tτ is less than Ts.

Referring to the system shown in Fig. 4, the signal on antenna 40 is amplified by broad-band amplifier 41 and its output SIN(τ) is applied as the input signal to band-limiting filter 42 which has a bandwidth equal to or less than 1/2 the sampling frequency fs of local oscillator 43 (which in this embodiment is a square wave source). Sampling clock signals fβ from source 43 are applied to sample-and-hold circuit 44 (which ha the form shown in Fig. 2a). The output of sample-and-hold circuit 44 is filtered by low pass filter 45 which has a center frequency which is about 1/2 of the sampler clock frequency f,, and the filtered output is supplied to a utilization device 46 for further processing. Low order aliases 47 and higher order aliases 48 are shown in Fig. 4b (line 2) (before low pas filter 45) and the output signal to the utilization device 46 is shown in Fig. 4b (line 3) .

Fig. 5a shows a receiver system similar to Fig. 4a but using a track-and-hold circuit 50 for producing the alias-driven frequency translation. In Fig. 5b (lines 1-4), graphically illustrates the single-sided frequency fa while Fig. 5 (line 2) illustrate the spectral output prior to the low pass filter 45' hold function (TH hold time); Fig. 5 (line 3) shows the spectral output (prior to low pass filter 41) track function τ = track time, and Fig. 5 (line 4) shows the spectral output signal SQUT (f)-

Fig. 6a shows the architecture for the alias-driven downconversion system of this invention using the sample-and-hold system described earlier, and Figs. 6b through 6g illustrate time and frequency domain aspects of the signal at test points TP4/ TP5 and TP6.

Figs. 7a and 7b provide graphical comparisons of spectrals of the system of Fig. la, lb (test point 3) with system of the present invention (test points in Fig. 6a).

Fig. 8a shows the architecture for the alias-driven downconversion system of this invention using the electronic track-and-hold system described earlier herein with the waveform at test points TP7, TPβ and TP9 being illustrated in figs. 8b through 8g.

Finally, Fig. 9 compares the spectral efficiency of frequency downconversion of the present invention with conventional mixer systems of the prior art. ADVANTAGES OF THE INVENTION:

Traditional frequency translation methods rely upon local oscillator frequencies equivalent to the magnitude of frequency translation desired. When using conventional mixers, it is necessary that the local oscillator frequency be equal to the magnitude of frequency translation desired. Typically, as these local oscillator frequencies become higher, circuit complexity, behavior, and electrical power consumption increase. This is especially true in oscillator implementations supporting a broad frequency tuning range and having requirements for fine frequency tuning resolution, precision, and accuracy. In simplifying local oscillator requirements, the method of Alias-Driven Translatio. of this invention offers several distinct advantages over the conventional method. These advantages are: Simplified tunable high resolution local oscillator design.

Figs. la and lb illustrate conventional approaches to high- resolution, precision tunable frequency translation. In the architecture of Fig. la, high-resolution, precision, and tunability are achieved using a numerically controlled oscillator. Since the tunable range of a numerically controlled oscillator (NCO) implemented as in Fig. la is restricted to frequencies below 0.5*clk (theoretical Nyquist limit) and approximately 0.4*^ (practical implementation limit), where Fclk represents the clock rate of the NCO and which itself has practical limitations, the NCO output is frequently augmented by heterodyning with a precision oscillator in order to shift the tunable range of the numerically controlled oscillator into usable range of local oscillator requirements. Using this approach for frequency translation provides a frequency tuning bandwidth restricted to the lesser of the tuning range of the NCO, and the filter bandwidth of Filter-B. Disadvantages of this implementation architecture include: narrow tuning range, high component count, and lowered reliability.

Fig. lb illustrates an approach to synthesizing high- resolution, precision frequencies for local oscillator implementation by selectively bandpass filtering for a high order frequency spur generated by a numerically controlled oscillator at the output of a digital-to-analog converter. Using this method for frequency translation provides a frequency tuning bandwidth restricted to the lesser of the tuning range of the NCO and the filter bandwidth of the bandpass reconstruction filter, Filter-A. Because of the amplitude degradation associated with higher order spurious response out of the NCO, it is often necessary to provide signal amplification to the selected frequency spur. Disadvantages of this implementation architecture include: a narrow tuning range restricted by the need for a bandpass reconstruction filter, increased local oscillator phase noise and the increased power consumption necessary to support the high frequency amplifiers (both due to the degraded amplitude of the selected frequency spur), and the need for a high-performance digital-to-analog converter featuring the high output slew rates and fast settling time necessary to generate the desired high frequency spurious response and to suppress undesired frequency spur generation.

As described above and illustrated in the drawings, downconversion according to this invention provide a broad IF tuning range with enhanced spectral power efficiency.

The invention has a broad input signal range resulting in circuit simplification compared to conventional approaches when building a system with equivalent functionality. For example, the invention can be used to cover IF ranges from DC to 1 GHz (with sub-Hertz resolution) using currently available technology and with substantially no circuit modification.

While preferred embodiments of the invention have been described and illustrated, it will be appreciated that other embodiments, adaptations and modifications of the invention will be readily apparent to those skilled in the art.

WHAT IS CLAIMED IS:

Claims

1. In a receiver system having an antenna RF amplifier coupled to said antenna for receiving intelligence modulated RF signals and producing a received intelligence modulated (RIM) RF signal and means for downconverting said RIM RF signal for use by a utilization circuit, the improvement in said means for downconverting comprising: first filter means connected to receive said RIM RF signal and having a first filter output, aliasing circuit means including electronic switch means connected to said first filter output, and a storage means connected to said switch means, means for producing signal, and switch control signal means for applying a control signal f, to said electronic switch to connect and disconnect said RIM RF signal to said storage means, a low pass filter means having a center frequency fc <_ 1/2 Fs connected to said storage means, and means connecting said low pass filter means to said utilization circuit.
2. The receiver system defined in claim 1 wherein said aliasing circuit means is a sample-and-hold circuit.
3. The receiver system defined in claim 1 wherein said aliasing circuit means is a track-and-hold circuit.
4. In a receiver system having an antenna RF amplifier coupled to said antenna for receiving intelligence modulated RF signals and producing a received intelligence modulated (RIM) RF signal and means for downconverting said RIM RF signal for use by a utilization circuit, the improvement in said method for downconverting comprising: enhancing spectral power efficiency using alias-driven frequency translation of received intelligence modulated RF signals, and low pass filtering the aliased signal.
5. The invention defined in claim 4 wherein the downconversion is in the IF ranges from DC to 1 GHz (with sub- Hertz) resolution).
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PCT/US1995/008233 1994-07-13 1995-07-13 Method and apparatus for alias-driven frequency downconversion (mixing) WO1996002977A1 (en)

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Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000022725A1 (en) * 1998-10-15 2000-04-20 Motorola, Inc. Product detector and method therefor
WO2000024117A1 (en) * 1998-10-21 2000-04-27 Parker Vision, Inc. Method and system for down-converting an electromagnetic signal
WO2000024119A1 (en) * 1998-10-21 2000-04-27 Parkervision, Inc. Applications of universal frequency translation
WO2001011767A1 (en) * 1999-08-04 2001-02-15 Parkervision, Inc. Modem for wireless local area network
WO2001071906A2 (en) * 2000-03-22 2001-09-27 Parkervision, Inc. Integrated frequency translation and selectivity with gain control functionality, and applications thereof
WO2001089078A2 (en) * 2000-05-16 2001-11-22 Parkervision, Inc. Apparatus, system, and method for down-converting and up-converting electromagnetic signals
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
GB2368476A (en) * 1998-10-21 2002-05-01 Parkervision Inc Down-converting an electromagnetic signal
US6421534B1 (en) 1998-10-21 2002-07-16 Parkervision, Inc. Integrated frequency translation and selectivity
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
EP1315285A2 (en) * 1998-10-21 2003-05-28 Parker Vision, Inc. Method and system for down-converting an electromagnetic signal
US6647250B1 (en) 1998-10-21 2003-11-11 Parkervision, Inc. Method and system for ensuring reception of a communications signal
US6694128B1 (en) 1998-08-18 2004-02-17 Parkervision, Inc. Frequency synthesizer using universal frequency translation technology
US6704558B1 (en) 1999-01-22 2004-03-09 Parkervision, Inc. Image-reject down-converter and embodiments thereof, such as the family radio service
US6704549B1 (en) 1999-03-03 2004-03-09 Parkvision, Inc. Multi-mode, multi-band communication system
EP1135853B1 (en) * 1998-10-21 2004-09-08 Parkervision, Inc. Integrated frequency translation and selectivity with a variety of filter embodiments
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
US7653158B2 (en) 2001-11-09 2010-01-26 Parkervision, Inc. Gain control in a communication channel
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
US7693230B2 (en) 1999-04-16 2010-04-06 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
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
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
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
US7894789B2 (en) 1999-04-16 2011-02-22 Parkervision, Inc. Down-conversion of an electromagnetic signal with feedback control
US7991815B2 (en) 2000-11-14 2011-08-02 Parkervision, Inc. Methods, systems, and computer program products for parallel correlation and applications thereof
US8019291B2 (en) 1998-10-21 2011-09-13 Parkervision, Inc. Method and system for frequency down-conversion and frequency up-conversion
US8160196B2 (en) 2002-07-18 2012-04-17 Parkervision, Inc. Networking methods and systems
US8233855B2 (en) 1998-10-21 2012-07-31 Parkervision, Inc. Up-conversion based on gated information signal
US8295406B1 (en) 1999-08-04 2012-10-23 Parkervision, Inc. Universal platform module for a plurality of communication protocols
US8407061B2 (en) 2002-07-18 2013-03-26 Parkervision, Inc. Networking methods and systems

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3573626A (en) * 1968-03-29 1971-04-06 Gen Dynamics Corp Automatic radio frequency pulse measurement system
US4673916A (en) * 1982-03-26 1987-06-16 Victor Company Of Japan, Limited Method and system for decoding a digital signal using a variable frequency low-pass filter
US4893088A (en) * 1988-11-16 1990-01-09 Harris Corporation Transimpedance focal plane processor
US4990911A (en) * 1988-04-08 1991-02-05 Sony Corporation Sampling frequency converter
US5050474A (en) * 1988-04-13 1991-09-24 Namco Ltd. Analog signal synthesizer in PCM
US5339459A (en) * 1992-12-03 1994-08-16 Motorola, Inc. High speed sample and hold circuit and radio constructed therewith

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3573626A (en) * 1968-03-29 1971-04-06 Gen Dynamics Corp Automatic radio frequency pulse measurement system
US4673916A (en) * 1982-03-26 1987-06-16 Victor Company Of Japan, Limited Method and system for decoding a digital signal using a variable frequency low-pass filter
US4990911A (en) * 1988-04-08 1991-02-05 Sony Corporation Sampling frequency converter
US5050474A (en) * 1988-04-13 1991-09-24 Namco Ltd. Analog signal synthesizer in PCM
US4893088A (en) * 1988-11-16 1990-01-09 Harris Corporation Transimpedance focal plane processor
US5339459A (en) * 1992-12-03 1994-08-16 Motorola, Inc. High speed sample and hold circuit and radio constructed therewith

Cited By (63)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6694128B1 (en) 1998-08-18 2004-02-17 Parkervision, Inc. Frequency synthesizer using universal frequency translation technology
US6230000B1 (en) 1998-10-15 2001-05-08 Motorola Inc. Product detector and method therefor
WO2000022725A1 (en) * 1998-10-15 2000-04-20 Motorola, Inc. Product detector and method therefor
US7697916B2 (en) 1998-10-21 2010-04-13 Parkervision, Inc. Applications of universal frequency translation
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
GB2358096A (en) * 1998-10-21 2001-07-11 Parkervision Inc Method and system for down-converting an electromagnetic signal
US8233855B2 (en) 1998-10-21 2012-07-31 Parkervision, Inc. Up-conversion based on gated information signal
WO2000024119A1 (en) * 1998-10-21 2000-04-27 Parkervision, Inc. Applications of universal frequency translation
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
US8160534B2 (en) 1998-10-21 2012-04-17 Parkervision, Inc. Applications of universal frequency translation
US6421534B1 (en) 1998-10-21 2002-07-16 Parkervision, Inc. Integrated frequency translation and selectivity
JP2002319826A (en) * 1998-10-21 2002-10-31 Parkervision Inc Method and circuit for down-converting signal with use of complementary fet with enhanced dynamic range
GB2358096B (en) * 1998-10-21 2003-01-08 Parkervision Inc Method and system for down-converting a modulated carrier signal
US7936022B2 (en) 1998-10-21 2011-05-03 Parkervision, Inc. Method and circuit for down-converting a signal
US7937059B2 (en) 1998-10-21 2011-05-03 Parkervision, Inc. Converting an electromagnetic signal via sub-sampling
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
WO2000024117A1 (en) * 1998-10-21 2000-04-27 Parker Vision, Inc. Method and system for down-converting an electromagnetic signal
US6580902B1 (en) 1998-10-21 2003-06-17 Parkervision, Inc. Frequency translation using optimized switch structures
US8019291B2 (en) 1998-10-21 2011-09-13 Parkervision, Inc. Method and system for frequency down-conversion and frequency up-conversion
US6647250B1 (en) 1998-10-21 2003-11-11 Parkervision, Inc. Method and system for ensuring reception of a communications 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
EP1315285A2 (en) * 1998-10-21 2003-05-28 Parker Vision, Inc. Method and system for down-converting an electromagnetic signal
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
EP1315285A3 (en) * 1998-10-21 2004-05-12 Parker Vision, Inc. Method and system for down-converting an electromagnetic signal
EP1135853B1 (en) * 1998-10-21 2004-09-08 Parkervision, Inc. Integrated frequency translation and selectivity with a variety of filter embodiments
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
US6836650B2 (en) 1998-10-21 2004-12-28 Parkervision, Inc. Methods and systems for down-converting electromagnetic signals, and applications thereof
GB2368476B (en) * 1998-10-21 2003-01-08 Parkervision Inc Method and apparatus for down-converting a modulated electromagnetic signal
US8190116B2 (en) 1998-10-21 2012-05-29 Parker Vision, Inc. Methods and systems for down-converting a signal using a complementary transistor structure
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
US8190108B2 (en) 1998-10-21 2012-05-29 Parkervision, Inc. Method and system for frequency up-conversion
GB2368476A (en) * 1998-10-21 2002-05-01 Parkervision Inc Down-converting an electromagnetic signal
US6704558B1 (en) 1999-01-22 2004-03-09 Parkervision, Inc. Image-reject down-converter and embodiments thereof, such as the family radio service
US6704549B1 (en) 1999-03-03 2004-03-09 Parkvision, Inc. Multi-mode, multi-band communication system
US7724845B2 (en) 1999-04-16 2010-05-25 Parkervision, Inc. Method and system for down-converting and 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
US7693230B2 (en) 1999-04-16 2010-04-06 Parkervision, Inc. Apparatus and method of differential IQ frequency up-conversion
US8224281B2 (en) 1999-04-16 2012-07-17 Parkervision, Inc. Down-conversion of an electromagnetic signal with feedback control
US7929638B2 (en) 1999-04-16 2011-04-19 Parkervision, Inc. Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments
US8223898B2 (en) 1999-04-16 2012-07-17 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, and transforms for same
US8229023B2 (en) 1999-04-16 2012-07-24 Parkervision, Inc. Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments
US8036304B2 (en) 1999-04-16 2011-10-11 Parkervision, Inc. Apparatus and method of differential IQ frequency up-conversion
US7894789B2 (en) 1999-04-16 2011-02-22 Parkervision, Inc. Down-conversion of an electromagnetic signal with feedback control
US8594228B2 (en) 1999-04-16 2013-11-26 Parkervision, Inc. Apparatus and method of differential IQ frequency up-conversion
US8077797B2 (en) 1999-04-16 2011-12-13 Parkervision, Inc. Method, system, and apparatus for balanced frequency up-conversion of a baseband signal
WO2001011767A1 (en) * 1999-08-04 2001-02-15 Parkervision, Inc. Modem for wireless local area network
US8295406B1 (en) 1999-08-04 2012-10-23 Parkervision, Inc. Universal platform module for a plurality of communication protocols
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
WO2001071906A2 (en) * 2000-03-22 2001-09-27 Parkervision, Inc. Integrated frequency translation and selectivity with gain control functionality, and applications thereof
WO2001071906A3 (en) * 2000-03-22 2003-10-16 Parkervision Inc Integrated frequency translation and selectivity with gain control functionality, and applications thereof
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
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
WO2001089078A2 (en) * 2000-05-16 2001-11-22 Parkervision, Inc. Apparatus, system, and method for down-converting and up-converting electromagnetic signals
WO2001089078A3 (en) * 2000-05-16 2003-01-30 Parkervision Inc Apparatus, system, and method for down-converting and up-converting electromagnetic signals
US7991815B2 (en) 2000-11-14 2011-08-02 Parkervision, Inc. Methods, systems, and computer program products for parallel correlation and applications thereof
US7653158B2 (en) 2001-11-09 2010-01-26 Parkervision, Inc. Gain control in a communication channel
US8446994B2 (en) 2001-11-09 2013-05-21 Parkervision, Inc. Gain control in a communication channel
US8407061B2 (en) 2002-07-18 2013-03-26 Parkervision, Inc. Networking methods and systems
US8160196B2 (en) 2002-07-18 2012-04-17 Parkervision, Inc. Networking methods and systems

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