DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on … is in compliance with the provisions of 35 CFR 1.97. Accordingly, the IDS has been considered by the examiner.
Response to Amendment
Claim 1 amended.
Claims 1-9 pending.
Response to Arguments
Applicant's arguments filed 10/10/2025 have been fully considered but they are not persuasive.
Applicant argues that “Mirzaie does not disclose a control signal from the processing circuit causing a change in the suppression band” and that “The cited art, thus, does not disclose or suggest” the newly added wherein clause limitations.
Regarding Applicant’s argument that “Mirzaie does not disclose a control signal from the processing circuit causing a change in the suppression band”:
This argument reads limitations into the claim that are not present. The claim recites “a control signal” and that the filter is “configured to change a suppression band…based on the control signal.” The claim does not require that the control signal be separate from or independent of the transmission generation circuitry, nor does it require active programmable control. Mirzaie’s transmitter local oscillator signals (TX_LO) are control signals generated by processing circuitry (the transmitter with its local oscillator). These signals control switches 402, 404, 406, 408 that determine where the notch appears. When the transmission frequency changes, the TX_LO signals change, causing the notch position to change correspondingly. This is a “change” in the “suppression band” that occurs “based on the control signal.” The fact that Mirzaie’s control mechanism is tied to the transmission frequency generation does not exclude it from the scope of the claim. The claim language is broad enough to encompass both active programmable control and passive frequency-tracking control, as long as there is (1) a control signal, (2) from processing circuitry, (3) that causes the suppression band to change. Mirzaie et al. (‘349) explicitly teaches this limitation.
Mirzaie et al. (‘349) teaches that the transmitter’s local oscillator (processing circuit) outputs TX_LO signals (control signals) to the switches in the notch filter circuit ([0020]; Fig. 4). These switches and impedance elements form the suppression band variable filter. Mirzaie et al. (‘349) further teaches that “a frequency notch signal can be generated at the frequency fTX” to suppress the TX leakage signal while the desired receiver signal fRX is not substantially affected ([0021]). This means the filter suppresses signals at the transmission frequency channel while passing signals at different frequency channels. Mirzaie et al. (‘349) teaches that this suppression occurs during transmission. The entire purpose of Mirzaie’s system is to suppress transmitter leakage “prior to demodulation of a desired receiver signal by a receiver” (Abstract). The system must operate “while” transmission is occurring to prevent transmitter leakage from interfering with reception. This is the fundamental operating principle of a full-duplex system where transmission and reception occur simultaneously.
Regarding Applicant’s argument about the wherein clause: Applicant argues that “The cited art does not disclose or suggest” the wherein clause because Mirzaie’s control signals do not “causes a change” in the suppression band. However, this argument conflates the mechanism by which control is achieved with the claimed structure and function. The claim does not require that the control signal be independently programmable or separate from transmission generation. It only requires that: A processing circuit outputs a control signal to the filter (Mirzaie’s TX_LO), the filter suppresses TX frequency (Mirzaie [0021]), the filter passes different frequencies (Mirzaie [0021]), this occurs while transmitting (Mirzaie’s full-duplex operation). All of these limitations are explicitly taught by Mirzaie et al. (‘349). The claim language “such that” describes the result of the control signal operation, not a specific mechanism. Mirzaie et al. (‘349) achieves this result through frequency shifting based on TX_LO signals. Whether the suppression band “changes” dynamically during operation or tracks the transmission frequency is not specified in the claim. Both interpretations satisfy the claim language. Klinnert et al. (‘586) teaches additional features regarding filter implementation in radar systems (Abstract; claims 1-5) and would have been used in combination with and Mirzaie et al. (‘349) to optimize the filter design.
One of ordinary skill in the art would have been motivated to incorporate Mirzaie’s transmitter leakage suppression system into Mulder’s radar device to reduce interference between transmission and reception paths, thereby improving signal-to-noise ratio and system performance. This combination would be obvious because:
Both Mulder et al. (‘341) and Mirzaie et al. (‘349) deal with full-duplex systems where transmission and reception occur simultaneously or in quick succession
Transmitter leakage is a well-known problem in radar and communication systems
Mirzaie’s solution directly addresses this known problem
The combination would yield predictable results: reduced interference and improved reception quality
The combination would have been obvious to try, with a reasonable expectation of success, as both references operate in related fields (radar and full-duplex communications) addressing the same fundamental problem of isolating transmission signals from reception paths. The claim language is broad enough to encompass Mirzaie’s frequency-tracking approach, and Applicant has not added language that would explicitly exclude this approach (such as “independently selectable,” “programmable,” or “separate from local oscillator signals”).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-9 are rejected under 35 U.S.C. 103 as being unpatentable over Mulder et al. (US 4,136,341) in view of Mirzaie et al. (US 2013/0272349 A1) and further in view of Klinnert et al. (US 2005/0179586 A1).
Regarding Claim 1, Mulder et al. (‘341) teaches:
Mulder et al. (‘341) teaches A radar device comprising (Abstract: “A radar system comprises a first generator for generating frequency modulated transmitter pulses of relatively long duration and a second generator for generating transmitter pulses of relatively short duration“):
Mulder et al. (‘341) teaches an antenna to transmit a plurality of transmission signals each of which has a different frequency to a target, individually, and acquire a reception signal by receiving a reflection signal reflected from the target (col. 2, lines 33-38: “The transmitter pulses produced by the two generators and transformed in frequency in this manner are combined by a unit 21 in a common r.f. channel and transmitted via an r.f. amplifier 22, a circulator 23 and an antenna unit 24“; col. 2, lines 46-47: “The return signals received by the antenna unit 24 are also supplied to a receiver 25 via the circulator 23“);
Mulder et al. (‘341) teaches a circulator to output the plurality of transmission signals each of which has been input from a transmission side at different timing to the antenna, individually, and output the reception signal acquired by the antenna to a reception side (col. 2, lines 33-47: “transmitted via an r.f. amplifier 22, a circulator 23 and an antenna unit 24” and “The return signals received by the antenna unit 24 are also supplied to a receiver 25 via the circulator 23“; col. 2, lines 46-68; Fig. 1, elements 26, 28); and
Mulder et al. (‘341) teaches processing circuit configured to generate a control signal and control transmission of the plurality of transmission signals; Mulder et al. (‘341) teaches processing circuitry including oscillator 19 and associated control elements that generate signals controlling transmission (col. 4, lines 25-35; Fig. 1). While Mulder et al. (‘341) not explicitly disclose that this processing circuit generates a control signal specifically for controlling a suppression band variable filter, Mirzaie et al. (‘349) teaches this feature as discussed below.
Mulder et al. (‘341) not explicitly teach, but Mirzaie et al. (‘349) teaches and a suppression band variable filter to which the reception signal output by the circulator to the reception side is input, the suppression band variable filter configured to change a suppression band of the suppression band variable filter to suppress a signal of a same frequency channel as a frequency channel of the transmission signal and pass a signal of a frequency channel different from the frequency channel of the transmission signal based on the control signal, Mulder et al. (‘341) not explicitly teach a suppression band variable filter as recited. However, Mirzaie et al. (‘349) teaches this feature. Mirzaie et al. (‘349) teaches a notch filter system for suppressing transmitter leakage signals in full-duplex transceivers (Abstract; [0018]-[0021]; Figs. 3-4). Specifically, Mirzaie et al. (‘349) teaches :
Processing circuit that generates control signals: Mirzaie et al. (‘349) teaches a transmitter including processing circuitry with a local oscillator that generates transmitter local oscillator signals (TX_LO) ([0020]-[0021]; Fig. 4, elements LO1, LO2, LO3, LO4). The transmitter local oscillator signals serve as control signals that determine the operation of the notch filter.
Variable filter that changes suppression band: Mirzaie’s notch filter circuit includes switches 402, 404, 406, and 408 that are “driven by local oscillators LO1, LO2, LO3 and LO4” ([0020]; Fig. 4). These switches connect to impedance elements ZBB(s) 410, 412, 414, and 416. The system operates based on “frequency shifting or translation of a low-quality factor (Q) baseband impedance ZBB(f) 422 to obtain a high Q band pass filter notch Zin(f) 420” ([0020]).
Changes suppression band based on control signal: Mirzaie et al. (‘349) explicitly teaches that “Zin(f) 420 can be frequency shifted to the radio frequency, e.g., by the frequency of the transmitter local oscillators LO1, LO2, LO3 and LO4” ([0021]). This frequency shifting is the mechanism by which the suppression band changes. The transmitter local oscillator signals (TX_LO) directly control where the notch appears in the frequency spectrum.
Suppresses TX frequency, passes other frequencies: Mirzaie et al. (‘349) teaches that “on the radio frequency side a frequency notch signal can be generated at the frequency fTX and applied to point A in the circuit 400 to attenuate the TX leakage signal” while “substantially not affecting the RX frequency of the desired receiver signal fRX” ([0021]). This demonstrates suppression of the transmission frequency channel while passing different frequency channels.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to combine the radar system of Mulder et al. (‘341) with the transmitter leakage suppression system of Mirzaie et al. (‘349). One would have been motivated to do so because Mulder et al. (‘341) describes a radar system that must deal with both transmit and receive signals through the same antenna system via a circulator (col. 2, lines 33-47), which inherently creates transmitter leakage problems that interfere with the reception of weak return signals. Mirzaie et al. (‘341) specifically addresses this exact problem by providing a notch frequency signal generation system that “attenuate[s] the transmitter leakage signal prior to demodulation of a desired receiver signal” ([0028]). The motivation would be to improve the signal-to-noise ratio and sensitivity of the Mulder et al. (‘341) radar system by eliminating the transmitter leakage that would otherwise mask weak target returns, which is a known and persistent problem in radar systems using shared transmit/receive antennas. The Mirzaie et al. (‘349) system is particularly well-suited for this application because it automatically tracks the transmission frequency and provides selective suppression only at that frequency, preserving the radar’s ability to receive return signals at the same nominal frequency but with Doppler shifts or other frequency variations that indicate target movement or characteristics.
Mirzaie et al. (‘349) explicitly teaches wherein the processing circuit is configured to output the control signal to the suppression band variable filter such that the suppression band variable filter suppresses a signal of a same frequency channel as a frequency channel of the transmission signal and passes a signal of a frequency channel different from the frequency channel of the transmission signal while the circulator outputs any one transmission signal out of the plurality of transmission signals to the antenna and the antenna transmits the transmission signal. Mirzaie et al. (‘349) teaches that the transmitter’s local oscillator (processing circuit) outputs TX_LO signals (control signals) to the switches in the notch filter circuit ([0020]; Fig. 4). These switches and impedance elements form the suppression band variable filter. Mirzaie et al. (‘349) further teaches that “a frequency notch signal can be generated at the frequency fTX” to suppress the TX leakage signal while the desired receiver signal fRX is not substantially affected ([0021]). This means the filter suppresses signals at the transmission frequency channel while passing signals at different frequency channels. Critically, Mirzaie et al. (‘349)teaches that this suppression occurs during transmission. The entire purpose of Mirzaie’s system is to suppress transmitter leakage “prior to demodulation of a desired receiver signal by a receiver” ([0018]; Abstract). The system must operate “while” transmission is occurring to prevent transmitter leakage from interfering with reception. This is the fundamental operating principle of a full-duplex system where transmission and reception occur simultaneously.
Regarding Claim 2, Mulder et al. (‘341) in view of Mirzaie et al. (‘349) teaches the radar device according to claim 1,
Mulder et al. (‘341) does not explicitly teach, but Mirzaie et al. (‘349) teaches wherein while transmission of the transmission signal by the antenna stops, the suppression band variable filter passes all input signals ([0029]: “Since the baseband impedance information is used to determine both transmitter leakage and PA driver distortion, the baseband impedance information can be used to save power on both the transmitter and receiver ends.”; [0028]: “The distortion information can be stored as pre-distortion information in digital buffer 710” – indicating dynamic control based on transmission state; [0030]: “Alternative and additional components may be used depending on an implementation. For example, the receiver may be used with various types of communication systems“).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to implement the Mirzaie et al. (‘349) filtering system in the Mulder et al. (‘341) radar with timing control. One would have been motivated to do so because during transmit periods, the suppression filter needs to block the transmitter frequency to prevent leakage, but during receive-only periods when no transmission occurs, blocking any frequencies would unnecessarily limit the receiver’s ability to detect return signals across the full spectrum. This timing-based control maximizes receiver sensitivity during receive periods while providing necessary protection during transmit periods.
Regarding Claim 3, Mulder et al. (‘341) in view of Mirzaie et al. (‘349) teaches the radar device according to claim 1,
Mulder et al. (‘341) does not explicitly teach, but Mirzaie et al. (‘349) teaches wherein the suppression band variable filter is a tunable filter ([0030]: “Alternative and additional components may be used depending on an implementation“; Abstract: “a switch controlled by the transmitter local oscillator signal, the switch connected with an impedance element to generate a notch frequency signal” – showing the variable nature of the impedance element controlling the notch frequency).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to make the Mirzaie et al. (‘349) suppression filter tunable when combined with the Mulder et al. (‘341) system. One would have been motivated to do so because Mulder et al. (‘341) operates with “frequency-modulated transmitter pulses” and “transmitter pulses” at different frequencies (Abstract), requiring the suppression filter to be adjustable to match whichever transmission frequency is currently being used. A fixed filter would only work for one frequency, but tunability allows the same hardware to suppress leakage from multiple transmission frequencies used in the Mulder et al. (‘341) system.
Regarding Claim 4, Mulder et al. (‘341) in view of Mirzaie et al. (‘349) teaches the radar device according to claim 1,
Mulder et al. (‘341) does not explicitly teach, but Mirzaie et al. (‘349) teaches wherein the suppression band variable filter includes a plurality of band rejection filters ([0028]: “The voltage information VBB I and VBB Q can be determined from an error vector magnitude (EVM) and adjacent channel leakage ratio (ACLR) for the baseband side of the notch. The voltage information VBB I and VBB Q can then be digitized from an analog-to-digital converter” – describing multiple signal processing elements working together for comprehensive filtering).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to implement multiple band rejection filters in the combined system. One would have been motivated to do so because the Mulder et al. (‘341) system uses “a first generator for generating frequency-modulated transmitter pulses” and “a second generator for generating transmitter pulses” (Abstract) operating at different frequencies simultaneously or in sequence. Multiple band rejection filters would allow simultaneous suppression of leakage from multiple transmission frequencies, providing better overall leakage suppression than a single filter could achieve across the multiple frequency bands used in the Mulder et al. (‘341) radar system.
Regarding Claim 5, Mulder et al. (‘341) in view of Mirzaie et al. (‘349) teaches the radar device according to claim 1, further comprising:
Mulder et al. (‘341) does not explicitly teach, but Mirzaie et al. (‘349) teaches noise signal suppressing circuitry to suppress a noise signal accompanying the transmission signal, included in the signal passed through the suppression band variable filter while the circulator outputs any one transmission signal out of the plurality of transmission signals to the antenna and the antenna transmits the transmission signal (Abstract: “The notch frequency signal is added to a transmitter leakage signal to attenuate the transmitter leakage signal prior to demodulation of a desired receiver signal“; [0029]: “The pre-distortion information can be inputted to the digital-to-analog converter (DAC) 720 for pre-distorting the TX signal“).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add noise suppression circuitry to the combined system. One would have been motivated to do so because Mulder et al. (‘341) describes the need for optimal clutter suppression (col. 1, lines 40-43: “A better clutter suppression can however be obtained by increasing the pulse repetition frequency, but this will be at the expense of the range of the radar system“), and noise accompanying the transmission signal would degrade this clutter suppression capability. Adding noise suppression circuitry as taught by Mirzaie et al. (‘349) would improve the overall signal quality and enhance the radar’s ability to distinguish between true target returns and unwanted clutter or noise signals.
Regarding Claim 6, Mulder et al. (‘341) in view of Mirzaie et al. (‘349) teaches the radar device according to claim 5,
Mulder et al. (‘341) does not explicitly teach, but Mirzaie et al. (‘349) teaches wherein the noise signal suppressing circuitry is a decoupling circuit ([0028]: “The voltage information VBB I and VBB Q can then be digitized from an analog-to-digital converter. The digitized information can be used to determine both transmitter leakage and PA driver distortion” – describing circuitry that decouples and isolates different signal components).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to implement the noise suppression as a decoupling circuit. One would have been motivated to do so because decoupling circuits are well-known for isolating unwanted signal coupling between transmit and receive paths, which is exactly the problem addressed in radar systems like Mulder’s that share antenna resources between transmission and reception functions.
Regarding Claim 7, Mulder et al. (‘341) in view of Mirzaie et al. (‘349) teaches the radar device according to claim 1,
Mulder et al. (‘341) and Mirzaie et al. (‘349) do not explicitly teach, but Klinnert et al. (‘586) does teach wherein the plurality of transmission signals is an LPRF transmission signal and an HPRF transmission signal having frequencies different from each other ([0004-0008], [0073]: “at least two spaced-apart radar sensors 71 and 72, which are each equipped for transmitting and receiving operation. The direct echoes are denoted by 711 and 721. They are reflected off of wall 8. Object 9 in the nearfield of the radar sensors cannot be detected by these direct echoes 92“; [0073]: “cross-echo Doppler 92 first appears, conditionally upon the shorter propagation time. Cross-echo Doppler 91 appears with a delay that is dependent on the propagation time“).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to combine the Mulder et al. (‘341) radar system with the LPRF/HPRF approach of Klinnert et al. (‘586). One would have been motivated to do so because Mulder et al. (‘341) specifically discusses the trade-off between pulse repetition frequency and range detection capability (col. 1, lines 44-53: “When using a pulse repetition frequency of say 2000 Hz, the detection of targets is limited to a range of 50 to 60 km” versus the need for “detection of targets at a range of 200 to 250 km“). Klinnert et al. (‘586) teaches using different operational modes specifically to address this exact problem – providing both long-range and short-range detection capabilities. The motivation is to overcome the fundamental limitation identified in Mulder et al. (‘341) by implementing the multi-mode solution approach taught in Klinnert et al. (‘586).
Regarding Claim 8, Mulder et al. (‘341) in view of Mirzaie et al. (‘349) teaches the radar device according to claim 1,
Mulder et al. (‘341) does not explicitly teach, but Mirzaie et al. (‘349) teaches further comprising: control signal generating circuitry to generate a control signal that changes a suppression band to be suppressed by the suppression band variable filter (Abstract: “a switch controlled by the transmitter local oscillator signal, the switch connected with an impedance element to generate a notch frequency signal“; [0028]: “The distortion information can be stored as pre-distortion information in digital buffer 710“).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add control signal generating circuitry to dynamically adjust the suppression band. One would have been motivated to do so because the Mulder et al. (‘341) system operates with multiple different transmission frequencies and timing sequences (Abstract describes “frequency-modulated transmitter pulses” and “transmitter pulses” of different characteristics), requiring the suppression filter to adaptively change its suppression characteristics to match the current transmission parameters. Dynamic control ensures optimal leakage suppression regardless of which transmission mode the radar is currently using.
Regarding Claim 9, Mulder et al. (‘341) in view of Mirzaie et al. (‘349) and Klinnert et al. (‘586) teaches a radar system comprising: a plurality of the radar devices according to claim 1, wherein each of the plurality of radar devices transmits a transmission signal having a different frequency and a different pulse repetition period to the target (Mulder et al. (‘341) describes multiple generators with different characteristics while Klinnert et al. (‘586) describes a plurality of radar devices [0073]: “at least two spaced-apart radar sensors 71 and 72, which are each equipped for transmitting and receiving operation“; [0073]: “The pulse modulation is carried out time-synchronously for all transmitter and receiver pairs“).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to create a system with multiple radar devices having different transmission characteristics. One would have been motivated to do so because both Mulder et al. (‘341) and Klinnert et al. (‘586) recognize that different radar parameters optimize performance for different scenarios – Mulder et al. (‘341) discusses the trade-offs between pulse repetition frequency and range capability, while Klinnert et al. (‘586) teaches using multiple sensors with different operating parameters to avoid interference and improve overall system performance. Combining multiple devices with different frequencies and pulse repetition periods would provide comprehensive coverage and detection capability across all range and clutter conditions, overcoming the individual limitations of any single radar configuration.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to REMASH R GUYAH whose telephone number is (571)270-0115. The examiner can normally be reached M-F 7:30-4:30.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Vladimir Magloire can be reached at (571) 270-5144. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/REMASH R GUYAH/Examiner, Art Unit 3648
/VLADIMIR MAGLOIRE/Supervisory Patent Examiner, Art Unit 3648