High Dynamic Range RF Power Detector

Abstract

A power meter system, method, and device are disclosed for measuring the power level of a radio frequency ("RF") input signal over a first input power detection range. The power meter includes a signal strength adjuster (SSA) that receives the RF input signal and adjusts the strength of the RF input signal by an adjustment amount in response to a control signal to generate an conditioned signal, and a rectifier that rectifies the conditioned signal to generate a rectified signal. The rectifier is limited to rectify over a rectifier input power detection range that is narrower than the first input power detection range. The rectified signal, in combination with the adjustment amount, represents the detected power in the RF input signal. The power meter further includes a controller that controls the SSA so that the conditioned signal falls within the detection range of the rectifier.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to the field of wireless communications, and more particularly to detecting radio frequency signals over a wide power range. [Background technology]

[0002] Conventional radio frequency power detectors may use rectifiers with a power detection range of, for example, 10 dB. Recent applications require wider power detection ranges than these conventional detectors can achieve. Given these limitations, a common solution for measuring radio frequency signals over a wide power range is to divide the power range into several sections, utilize multiple power detectors optimized for the individual limited power ranges corresponding to each section, and combine the final results. However, nonlinearities exist at the boundaries between these power detectors, transitioning from the high end of one power detector to the low end of the next. Furthermore, using multiple power detectors increases the cost, topology area, and power usage of the solution. Furthermore, such solutions often require extensive calibration. Thus, an improved wide power detection range solution for detecting the power level of radio frequency signals is desirable. Summary of the Invention

[0003] In an exemplary embodiment, a power meter for measuring the power level of a radio frequency ("RF") input signal over a first input power detection range is disclosed. The power meter includes a signal strength adjuster (SSA) that receives the radio frequency ("RF") input signal and, in response to a control signal, adjusts the strength of the RF input signal by an adjustment amount to generate an regulated signal. The power meter further includes a rectifier that rectifies the regulated signal to generate a rectified signal. The rectifier is limited to rectify over a rectifier input power detection range that is narrower than the first input power detection range. The rectified signal, in combination with the adjustment amount, represents the detected power in the RF input signal. The power meter further includes a controller that controls the SSA with a control signal based on the rectified signal so that the regulated signal falls within the detection range of the rectifier.

[0004] In an exemplary embodiment, a wireless communication system is disclosed. The wireless communication system includes a power meter for measuring the power level of a radio frequency ("RF") input signal. In this exemplary embodiment, the power meter includes a signal strength adjuster (SSA) that receives the radio frequency ("RF") input signal and adjusts the strength of the RF input signal by an adjustment amount in response to a control signal to generate an regulated signal, a rectifier that rectifies the regulated signal to generate a rectified signal representative of the detected power in the RF input signal, and a controller that provides a control signal to the SSA based on the rectified signal so that the regulated signal falls within a detection range of the rectifier.

[0005] In an exemplary embodiment, a method is disclosed for detecting power in a radio frequency ("RF") input signal over a detector operating input power range that is greater than the rectifier operating input power range of a single rectifier used in the detector. The method includes receiving the RF input signal at a signal strength adjuster (SSA), receiving at least one control signal at the SSA, adjusting the strength of the RF input signal based on an adjustment amount to generate an regulated signal, the adjustment amount being based on the at least one control signal, rectifying the regulated signal at the single rectifier to generate the rectified signal, a controller generating at least one control signal based on the rectified signal to cause the regulated signal to fall within the detection range of the single rectifier, and generating a power detector output signal representative of the power of the RF input signal based on the rectified signal and the amount of adjustment made by the SSA.

[0006] These and other features of the present invention will become apparent to those skilled in the art to which the present invention pertains from a reading of the following description taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 illustrates a portion of an exemplary power meter, according to an exemplary embodiment. [Figure 2] FIG. 2 illustrates a portion of another exemplary power meter, according to an exemplary embodiment. [Figure 3] FIG. 3 illustrates a portion of yet another example power meter including a discrete attenuator and a controller in accordance with an example embodiment. [Figure 4] FIG. 4 illustrates a method for dynamically detecting the power of an RF input signal over a range greater than the range of the rectifier performing the detection, according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Although exemplary embodiments are described herein in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and logical, electrical, and mechanical changes may be made without departing from the spirit and scope of the present invention. Thus, the following detailed description is given for purposes of example only.

[0009] In wireless communication systems or other systems that use radio frequency (“RF”) signals, the power level of a received or transmitted RF signal may be useful for performing processing on or with the RF signal. These systems may use one or more conventional power meters that measure or otherwise detect the power level of the RF signal. In many embodiments, these systems are exposed to RF signals having a wide range of power levels, and the operating range of each power meter may exceed the power detection range of one or more rectifiers used in the power meter to measure the power level of the RF signal. Therefore, a conventional power meter may not be able to measure the power level of a radio frequency signal that exceeds the power detection range of one or more rectifiers without increasing component cost, circuit complexity, or the like.

[0010] To overcome these drawbacks, exemplary embodiments of power meters described herein for use in such systems, and methods of use thereof, use a feedback mechanism to actively adjust the RF input signal to be within the power detection range of the respective rectifier(s). By enabling such adjustments to the RF signal, the power meters disclosed herein can generate accurate measurements of the power levels of RF signals within their operating range that would otherwise exceed the power detection range of the rectifier. According to various exemplary embodiments, the power meter's feedback mechanism effectively extends the operating range of the power meter without changing the power detection range of the rectifier and thus without increasing the power and area consumption of the power detector or the costs associated with the power detector compared to conventional power detectors.

[0011] According to various exemplary embodiments, a wireless communications system includes a power meter configured to measure the power level of an RF input signal, the power meter having an operating range greater than that suitable for conventional power meters. In exemplary embodiments, the power level of the RF input signal is greater than the power level limit (i.e., the power detection range) of a detecting rectifier. Although the power meters described herein are used in wireless communications systems, the power meters may be used in any suitable RF signal application, such as RADAR systems, cellular transceivers, satellite transceivers, and wireless signal monitoring systems.

[0012] According to an exemplary embodiment, a power meter includes a signal strength adjuster (SSA), a rectifier, and a controller. In the exemplary embodiment, the power meter is configured to measure the power level of an RF input signal over a first input power detection range (i.e., an operating power range) associated with the power meter. In the exemplary embodiment, the first input power detection range is a wide power range in which the rectifier may saturate if the power level of the RF input signal is not adjusted, for example, within the rectifier's power detection range. In the exemplary embodiment, the power meter utilizes feedback to the SSA to adjust the power level of the RF input signal provided to the rectifier. For example, the RF input signal may be provided through an SSA (such as a variable attenuator) that adjusts (e.g., attenuates) the power level of the RF input signal to fall within the rectifier's power detection range based on the feedback. The power meter is then configured to provide an accurate measurement of the power level of the RF input signal based on a combination of the rectified signal generated by the rectifier and the feedback (e.g., the amount of adjustment applied by the SSA).

[0013] More specifically, in an exemplary embodiment, the SSA is configured to receive an RF input signal and adjust the strength (i.e., power level) of the RF input signal to generate a conditioned signal. A rectifier may be configured to receive the conditioned signal and generate a rectified signal, which may be provided to a controller, which may be configured to provide a control signal to the SSA. The control signal to the SSA may correspond to the feedback described above. In a further exemplary embodiment, the controller is a comparator. In yet another exemplary embodiment, the power meter comprises a comparator and a controller. In this exemplary embodiment, the comparator is configured to provide a comparator signal to the controller, which is configured to provide a control signal to the SSA, which enables the controller to provide different values ​​to the SSA to adjust the RF input signal by different amounts. Further details are provided below with reference to the drawings. In particular, FIGS. 1-3 are block diagrams illustrating portions of a complete power meter or a subset of relevant components without showing or discussing details of various other known components of a power meter (which may be present in any practical application of the present disclosure and may be implicitly included herein).

[0014] According to an exemplary embodiment and with reference to FIG. 1 , a power meter 100 is disclosed. In this exemplary embodiment, the power meter 100 includes an SSA 110, a rectifier 120, and a controller 130. In the exemplary embodiment, the rectifier 120 is connected in signal communication between the SSA 110 and the controller 130, and the controller 130 is connected in signal communication between the rectifier 120 and the SSA 110. Signal communication between the controller 130 and the SSA 110 may correspond to or function as a control or feedback signal for the power meter 100. The power meter 100 further includes a power meter signal input 111 that receives an RF input signal for processing and / or monitoring. The power meter 100 further includes a power meter signal output 199 that outputs a measurement or indication of the power level of the RF input signal received at the power meter signal input 111. In an exemplary embodiment, power meter 100 further comprises a processor 180 for generating a power meter output signal at power meter signal output 199 based on one or more of the output signal from rectifier 120, a combination of the output signal from rectifier 120 and an adjustment amount related to the feedback signal, etc. Further details are provided below.

[0015] In an exemplary embodiment, SSA 110 is connected to or includes a power meter signal input 111, an SSA control signal input 112, and an SSA signal output 113. SSA 110 may be configured to receive an RF input signal at or from power meter signal input 111 and a control signal at or from SSA control signal input 112. The RF input signal may be a signal for a wireless communication system (e.g., a transceiver input / output signal), a signal indicating a power level of a circuit, a noise signal, a voltage controlled oscillator (VCO) generated signal, a monitored radio signal (e.g., a signal used in radio astronomy), or any other raw or processed RF signal.

[0016] In some embodiments, the control signal indicates to the SSA 110 the amount of adjustment to apply to the RF input signal. More specifically, the control signal may provide the SSA 110 with a value indicative of the amount of adjustment to apply to the RF input signal, or a value that the SSA 110 interprets to determine the amount of adjustment of the SSA 110, for example. The amount of adjustment corresponds to an amount of adjustment (e.g., attenuation or gain) to apply to the RF input signal that brings the power level or signal strength of the RF input signal within or closer to the power detection range of the rectifier 120. The SSA 110 may further be configured to adjust the power level of the RF input signal by or based on the amount of adjustment in response to the control signal and generate an adjusted signal at the SSA signal output 113. In one exemplary embodiment, the SSA 110 is an attenuator, such as a variable attenuator. In such an embodiment, the SSA 110 may therefore be configured to reduce the power in the RF input signal by a variable or fixed amount. The amount of reduction may be indicated by or determined based on the control signal when generating the adjusted signal, as described above. In another exemplary embodiment, the SSA 110 is a gain amplifier, such as a variable gain amplifier. In some such embodiments, the SSA 110 may be configured to increase the power in the RF input signal by a variable or fixed amount, where the amount of increase may be indicated by or determined based on a control signal. In some embodiments, the SSA 110 is a fixed gain amplifier configured to increase the power in the RF input signal by a fixed amount, where the amount of increase may be based on a predetermined value, function, etc., rather than being associated with or based on a control signal. Furthermore, the SSA 110 may be any device suitable for decreasing or increasing the gain, and therefore the power level, of the RF input signal by a desired (fixed or variable) adjustment amount.

[0017] In some embodiments, the desired adjustment amount is determined or selected based on the power detection range of the rectifier 120. For example, the desired adjustment amount may correspond to an amount suitable for causing the conditioned signal generated by the SSA 110 to have a power level within or near the power detection range of the rectifier 120. For example, the desired adjustment amount may be determined based on the output of the rectifier 120 exceeding one or more thresholds. Alternatively, the desired adjustment amount may be determined based on a prediction, estimation, look-up table, etc. configured to adjust the power level of the RF input signal to a value within or near the detection range of the rectifier 120. Thus, the adjustment amount received by the SSA 110 via the control signal may enable the SSA 110 to generate an conditioned signal having a power level within or near the power detection range of the rectifier 120 compared to the RF input signal without adjustment. In some embodiments, the SSA 110 may generate an conditioned signal without actually adjusting the RF input signal when the control signal indicates no adjustment is required.

[0018] In an exemplary embodiment, rectifier 120 is configured to receive the conditioned signal from SSA signal output 113, rectify the conditioned signal, and generate a rectified signal at rectifier output 123. This rectified signal may be indicative of or representative of the power level of the conditioned signal and, therefore, the RF input signal. In an exemplary embodiment, rectifier 120 generates as the rectified signal a direct current (DC) voltage proportional to the power level of the conditioned signal at SSA signal output 113. In other words, the rectified signal may represent the detected power in the conditioned signal.

[0019] In the exemplary embodiment, the combination of the rectified signal from rectifier 120 and the adjustment amount represents the detected power in the RF input signal, as described further below.

[0020] As noted above, in the exemplary embodiment, rectifier 120 is limited to rectifying the conditioned signal over or within a rectifier power detection range that is narrower than the first input power detection range of power meter 100. Therefore, if the first input power detection range is the operating input power range of power meter 100 at which power meter 100 can reliably detect the power level in the RF input signal and the rectifier detection range is the rectifier operating input power range at which rectifier 120 can reliably detect and rectify the power in the RF input signal, then the operating input power range of power meter 100 can be greater than the rectifier operating input power range of a single rectifier 120 of power meter 100. In the exemplary embodiment, the operating input power range of power meter 100 is greater than 40 dB, and the operating input power range of a single rectifier 120 of power meter 100 is 10 dB or less. Furthermore, in the exemplary embodiment, the first input power range is at least twice the rectifier input power range. The variation between the first input power detection range and the rectifier power detection range of power meter 100 may vary depending on the application. For example, the first input power detection range of power meter 100 may be many times greater (e.g., 10 times, 100 times, 1000 times, etc.) than the rectifier power detection range or rectifier operating input power of rectifier 120, or the first input power detection range of power meter 100 may be slightly greater (e.g., 10%, 50%, 100%, 200%, etc.) than the rectifier power detection range or operating input power of rectifier 120. In one exemplary embodiment, the operating input power range of the power meter is greater than 20 dB, and the operating input power range of the power meter's single rectifier is 10 dB or less. Therefore, but for the feedback discussed herein, where rectifier 120 saturates when measuring a power level of the power meter signal input that is within the operating input power range of power meter 100 but outside the rectifier operating input power range of rectifier 120, power meter 100 may not provide a reliable output.

[0021] In the exemplary embodiment, controller 130 is configured to receive a rectified signal representing the detected power in the conditioned signal from rectifier output 123. In this exemplary embodiment, controller 130 is further configured to compare the rectified signal to a preset threshold and generate a control signal at controller output 133. For example, controller 130 may include an operational amplifier or other component configured to compare the rectified signal to a threshold level and generate a control signal indicative of whether the rectified signal is below or above the threshold level.

[0022] Thus, the control signal may indicate whether the conditioned signal provided to rectifier 120 can be reliably measured by rectifier 120. For example, controller 130 may generate a control signal that indicates whether the signal strength of the conditioned signal generated by SSA 110 is within the power detection range of rectifier 120. In other words, controller 130 may generate a feedback signal such that power meter 100 generates a rectified signal at rectifier output 123 that is within a predetermined or defined range (e.g., within the power detection range of rectifier 120). In an exemplary embodiment, the control signal is a voltage level, current level, or otherwise indicates the value of a power level adjustment for SSA 110 to apply to the RF input signal.

[0023] In some embodiments, the predetermined threshold corresponds to, for example, an expected value or range of power levels to which the rectified signal is compared. The predetermined threshold may comprise or correspond to one or more of a power detection range of rectifier 120, a predetermined or desired power range, etc., any of which may be stored in or retrieved from memory or local storage, received or retrieved from rectifier 120, received from a user interface, etc.

[0024] Therefore, the power meter 100 may include a control loop or feedback loop 101 in which the controller 130 provides feedback (e.g., in the form of a control signal) to the SSA 110 based on the rectified signal from the rectifier 120, which feedback is used by the SSA 110 to control the amount of adjustment the SSA 110 makes to the RF input signal so that the conditioned signal provided to the rectifier 120 falls within the power detection range of the rectifier 120.

[0025] In contrast to conventional power meter topologies for wide power range detection, and in accordance with various exemplary embodiments presented herein, power meter 100 may not include parallel or cascaded rectifiers. Rather, in various exemplary embodiments, power meter 100 may include only a single rectifier 120.

[0026] As mentioned above, in the exemplary embodiment, power meter 100 includes processor 180 configured to generate a power meter output signal at power meter signal output 199 that represents or is indicative of the detected power in the RF input signal by power meter 100. In the exemplary embodiment, power meter 100 can generate the power meter output signal without the use of calibration for rectifier alignment and / or alignment of multiple rectifiers.

[0027] In an exemplary embodiment, the power meter output signal comprises or corresponds to a combination of the rectified signal at rectifier output 123 and the control signal at controller output 133. In an exemplary embodiment, processor 180 may back-calculate (or otherwise determine) the power level of the RF input signal based on the rectified signal, which indicates the power level of the rectified signal, and the amount of adjustment of the control signal, which indicates how the original RF input signal was adjusted to obtain the rectified signal. The amount of adjustment, in combination with the power level of the rectified signal, may determine the power level of the RF input signal. For example, processor 180 may receive the control signal, determine the amount of power compensated by the adjustment applied by SSA 110, and sum this amount of power with the power level indicated by the rectified signal to calculate the power level of the RF input signal. In some embodiments, for example, if controller 130 comprises a high-gain comparator, processor 180 may determine the detected power level of the RF input signal based on the comparator signal (and thus the power meter output signal may indicate the detected power level of the RF input signal) without having to receive or use the rectified signal.

[0028] In some embodiments described in this application, the control loop 101 is described in the context of a digital control loop. However, it is contemplated that other embodiments may include analog control loops with functionality similar to the digital control loops described herein. For example, the embodiment disclosed in FIG. 1 may be implemented as an analog control loop, e.g., by the controller 130 directly feeding back to the SSA 110 (as a variable attenuator or variable gain amplifier), with the controller 130's feedback indicating the amount of adjustment to apply to the SSA 110. In analog control loop embodiments, any stability concerns may be addressed by increasing settling time. For example, if the power meter 100 does not include any components between the controller 130 and the SSA 110, the controller 130 with a comparator may generate the control signal as a true analog output signal. Alternatively, in a power meter with a feedback controller / comparator, the comparator may provide a digital comparator signal to the feedback controller, which may generate the control signal as an analog or digital signal.

[0029] As mentioned above, in some embodiments, the SSA 110 receives a control signal from the controller 130 and uses the control signal to identify or control the amount of adjustment the SSA 110 applies to the RF input signal. For example, if the control signal is a digital control signal, the SSA 110 may change the amount of adjustment applied to the RF input signal when the control signal has a value of “0” and maintain the amount of adjustment applied when the control signal has a value of “1.” In some embodiments, the control signal is an analog control signal that indicates one or more of the amount of adjustment the SSA 110 previously applied to the RF input signal (e.g., in a previous iteration), the amount of adjustment the SSA 110 will apply to the RF input signal (e.g., in a next iteration), etc. For example, the SSA 110 may not apply any adjustment to the RF input signal in the first iteration. Thus, the controller 130 may generate an analog control signal (e.g., according to a binary search or similar algorithm) indicating that the SSA 110 should apply half of its maximum amount of adjustment when the conditioned signal is outside the operating input power range of the rectifier. More specifically, the analog control signal may identify the amount of adjustment the SSA 110 applies to the RF input signal, indicate a value equal to half the maximum adjustment amount of the SSA 110 (or the largest subsequent adjustment amount available), or indicate a value that instructs the SSA 110 to apply half of its maximum adjustment amount to the RF input signal. Thus, the SSA 110 may receive the analog control signal to apply the appropriate amount of adjustment to the RF input signal.

[0030] In some embodiments, the SSA 110 includes processing or similar components that enable the SSA 110 to interpret analog or digital control signals and, in response, identify the amount of adjustment to apply to the RF input signal. For example, when the SSA 110 receives a digital control signal with a value of “0,” the SSA 110 with processing components may modify the amount of adjustment applied to the RF input signal according to one or more of a binary search algorithm, iterative adjustment, etc. Alternatively, the SSA 110 simply responds to the analog or digital control signal without processing. For example, such an SSA 110 may receive an analog control signal indicating the amount of adjustment to apply to the RF input signal, and in response, the SSA 110 may activate appropriate components (e.g., activate respective attenuators as directed by or determined from analog control signals from a controller, an example of which is described below with reference to FIG. 3 ). Similarly, an SSA responsive to a digital control signal with a value of “0” may incrementally increase the amount of adjustment applied to the RF input signal when the digital control signal uses circuitry that does not perform any actual processing on the digital control signal.

[0031] In some embodiments, controller 130 uses a control signal to control the amount of attenuation by SSA 110. For example, if controller 130 includes a comparator, the comparator signal may indicate that the conditioned signal from SSA 110 is within the power detection range of rectifier 120, and a feedback controller may provide a control signal based on the comparator signal that causes SSA 110 to not change the amount of adjustment (e.g., attenuation or amplification) that SSA 110 applies to the RF input signal. On the other hand, if the comparator signal indicates that the conditioned signal from SSA 110 is not within the power detection range of rectifier 120, the comparator of controller 130 is configured to provide the comparator signal to the feedback controller, which generates a control signal that causes SSA 110 to adjust (e.g., iteratively adjust) the amount of adjustment that SSA 110 applies to the RF input signal so that the conditioned signal is within (or closer to) the power detection range of rectifier 120. As noted above, the control signal may indicate to the SSA 110 one or more amounts of adjustment to apply, that adjustment is needed, and so on.

[0032] In an exemplary embodiment, controller 130 includes a state machine, such as a successive approximation register (“SAR”) state machine, a counter, or the like. In this exemplary embodiment, the state machine uses a control signal to control the amount of attenuation by SSA 110. In this exemplary embodiment, the state machine may have a first state that causes controller 130 to generate a control signal that causes SSA 110 to not change the amount of adjustment, and a second state that causes controller 130 to generate a control signal that causes SSA 110 to change the amount of adjustment. The state machine may be configured to change between the first state and the second state based on whether the regulated signal from SSA 110 is within the detection range of rectifier 120.

[0033] As an example, if controller 130 includes a comparator and a state machine, when the comparator signal from the comparator indicates that the conditioned signal from SSA 110 is within the power detection range of rectifier 120, the state machine does not change state; it prevents the state machine from changing the control signal generated by controller 130, thereby preventing SSA 110 from changing the amount of adjustment (e.g., attenuation or amplification) that SSA 110 applies to the RF input signal. On the other hand, if the comparator signal indicates that the conditioned signal is not within the power detection range of rectifier 120, the state machine is configured to change state. In the new state, controller 130 is caused to output a control signal that causes SSA 110 to change the amount of adjustment. After SSA 110 changes the amount of adjustment, the rectified signal is rechecked to determine whether the conditioned signal is now within the power detection range of rectifier 120. If the conditioned signal is still not within the power detection range of rectifier 120, this process is repeated until the conditioned signal is within the power detection range of rectifier 120, after which the state machine changes state again to prevent further changes to the amount of adjustment. By changing state, controller 130 can use the control signal to adjust (e.g., iteratively adjust) the amount of adjustment that SSA 110 applies to the RF input signal so that the conditioned signal is within the power detection range of rectifier 120.

[0034] In this exemplary embodiment, the state machine is configured to change states through any method to generate appropriate state machine control signals based on the comparator signal to cause the SSA 110 to sufficiently adjust the attenuation or amplification of the RF input signal so that the final adjusted signal falls within the power detection range of the rectifier 120. For example, the state machine may have at least an “unsaturated” state and a “saturated” state. If the comparator signal indicates that the SSA 110 needs further adjustment, if the state machine is currently in the “saturated” state, it can return to the saturated state or remain in the saturated state, and the state machine generates control signals to cause the SSA 110 to adjust. If the state machine is in the unsaturated state and the comparator signal indicates that the SSA 110 needs adjustment, the state machine can change states to the saturated state to provide the appropriate control signals. On the other hand, if the comparator signal indicates that no further adjustment is necessary and the state machine is in a saturated state, the state machine may be changed from the saturated state to a desaturated state in which the state machine generates a control signal that causes the SSA 110 to not make further adjustments, or if the state machine is already in a desaturated state, it may simply return to or remain in that state.

[0035] In other exemplary embodiments, the state machine may use additional states, for example, to cause different amounts of adjustment in different states. The state machine may also be configured to use an iterative adjustment method. In this embodiment, the state machine includes states configured to generate control signals that incrementally adjust the SSA 110's attenuation or amplification of the RF input signal.

[0036] In one exemplary embodiment, and referring now to FIG. 2 , a portion of a power meter is disclosed that includes an exemplary control loop or feedback loop 201 for a power meter, such as power meter 100 of FIG. 1 . Not shown in FIG. 2 , for example, are components that output a signal power output. In one exemplary embodiment, power meter feedback loop 201 includes SSA 210 (similar to SSA 110), rectifier 220 (similar to rectifier 120), and controller 230. In this exemplary embodiment, controller 230 includes or corresponds to comparator 231 and feedback controller 232. In this exemplary embodiment, comparator 231 may determine whether the rectified signal is within an expected range (e.g., a power detection range of the rectifier) ​​and generate a corresponding binary comparator signal to feedback controller 232 (e.g., a “1” when within the expected range and a “0” when outside the expected range). For example, a power level of the rectified signal corresponding to the sustained or repeated maximum power output of rectifier 220 may indicate that the conditioned signal at the signal output of SSA 210 exceeds the expected range of rectifier 220. Therefore, upon receiving this rectified signal, comparator 231 of controller 230 may determine that the rectified signal is not within the expected range of rectifier 220 and generate a comparator signal having a binary value of "0." In some embodiments, comparator 231 may generate a comparator signal having a variable or analog value indicative of, for example, the difference between the expected range and the power level of the rectified signal, or the amount of adjustment applied to SSA 210. Comparator 231 provides the comparator signal to feedback controller 232, which may provide its feedback to SSA 210 via a control signal. In an exemplary embodiment, in the case of a variable value, the feedback may indicate one or more of the amount of adjustment of SSA 210 to apply to the RF input signal, the number of times or cycles the rectified signal exceeds an expected range, the number of adjustment steps of SSA 210 to apply to the RF input signal, etc. In this manner, SSA 210 may be configured to apply an appropriate power adjustment to the RF input signal based on the value of the control signal.Therefore, when the comparator signal has a variable value, the SSA 210 can use the feedback control signal to adjust the RF input signal to produce a regulated signal within the power detection range of the rectifier 220 .

[0037] For example, if the SSA 210 is a variable gain amplifier and the control signal indicates an adjustment amount, the SSA 210 may apply the indicated adjustment amount to the RF input signal to generate a corresponding conditioned signal that falls within the power detection range of the rectifier 220. Alternatively, if the SSA 210 is a variable attenuator and the comparator signal simply indicates (e.g., as a binary value) that the power level of the rectified signal is not within the power detection range of the rectifier 220, the SSA 210 may increase the amount of attenuation applied to the RF input signal to generate a corresponding conditioned signal. Such adjustments may be repeated iteratively until the SSA 210 generates an conditioned signal that falls within the power detection range of the rectifier 220.

[0038] Control loop 201 further includes a digital-to-analog converter ("DAC") 250 for receiving a digital signal from controller 230, converting the digital signal to an analog signal, and providing an analog control signal to SSA 210 at the control signal input, where SSA 210 expects the analog control signal. The use of a DAC may facilitate variable attenuation or variable amplification in SSA 210, to which feedback controller 232 provides one or more digital signals that DAC 250 converts to a control signal. The one or more digital signals may exhibit the feedback aspects described above. In one exemplary embodiment, SSA 210 is a variable attenuator, and DAC 250 is configured to provide a control signal to the variable attenuator based on an input received from controller 230 to control the amount of attenuation of the RF input signal. In another exemplary embodiment, SSA 210 is a variable gain amplifier, and DAC 250 is configured to provide a control signal to the variable gain amplifier to control the amount of amplification of the RF input signal.

[0039] In another exemplary embodiment (not shown), loop 201 includes an analog-to-digital converter (ADC). In this exemplary embodiment, the bit length (e.g., number of bits) of the signal generated by the controller may be determined by dividing the range of the RF input signal to be detected (e.g., the operating input power range of the power meter) by the step size of the detection or rectifier within that range (e.g., the operating input power range of the rectifier). For example, a power meter having a range of 0 to 35 dB (e.g., capable of receiving RF input signals within a range of 0 to 35 dB) and a rectifier step size of 5 dB may use a control signal with a bit length of 3 bits for seven available steps. In this manner, the value of this control signal may indicate the amount of adjustment to the RF input signal that will result in the adjusted signal falling within the operating input power range of the rectifier. In some embodiments, the control signal conveys one or more of the most significant bits (MSB) or least significant bits (LSB) of the bit length to the SSA, which may be used by the SSA to change the adjustment, etc., applied to the RF input signal.

[0040] Referring now to FIG. 3, in an exemplary embodiment, a portion of a power meter is shown illustrating an exemplary feedback loop 301 of the power meter. Components that output, for example, a signal power output are not shown in FIG. 3. In an exemplary embodiment, a control or feedback loop 301 of a power meter, such as power meter 100, includes an SSA 310 (similar to SSA 110) that includes any suitable number of discrete attenuators 310a-310n, a rectifier 320 (similar to rectifier 120), a comparator 340 (similar to comparator 231), and a controller 330 (similar to feedback controller 232). In this exemplary embodiment, each of the discrete attenuators 310a-310n may be configured to provide a discrete amount of attenuation that is different from the other discrete attenuators. In some embodiments, the discrete attenuators are active when adding attenuation (e.g., when discrete attenuator 310a is active, it applies 16 dB of attenuation) and inactive when not adding any attenuation (e.g., when discrete attenuator 310a is inactive, it applies 0 dB from discrete attenuator 310a). In an exemplary embodiment, controller 330 controls when each of these discrete attenuators 310a-310n attenuates the RF input signal.

[0041] In one exemplary embodiment not shown in FIG. 3, each discrete attenuator of SSA 310 provides the same amount of attenuation. For example, each of discrete attenuators 310a-310n may provide 1 dB of attenuation. As a result, when controller 330 instructs to apply 4 dB of attenuation, four discrete attenuators 310a-310n are activated. Controller 330 is configured to generate digital signals to control SSA 310, individually activating / deactivating discrete attenuators 310a-310n as appropriate to obtain the desired attenuation.

[0042] According to further exemplary embodiments, the controller 330 may be configured to determine which discrete attenuator(s) is most appropriate to activate / deactivate using a “thermometer” or similar algorithm that selectively activates the discrete attenuators 310a-310n to provide incremental changes in attenuation via the SSA 310. For example, via the thermometer algorithm, the controller 330 may first activate the first discrete attenuator 310a, then activate the second discrete attenuator 310b in combination with the first discrete attenuator 310a as needed, and then activate the third discrete attenuator 310c in combination with the first and second discrete attenuators 310a and 310b. If each of the discrete attenuators 310a-310n introduces the same amount of attenuation (e.g., each provides 1 dB of attenuation), this thermometer algorithm may cause the SSA 310 to incrementally increase the attenuation in 1 dB increments. In some embodiments, the controller 330 may use a thermometer algorithm when the discrete attenuators provide different amounts of attenuation, but provide similar characteristics of stepped attenuation increases in different increments, as shown in Figure 3. For example, the controller 330 may stepwise increase the attenuation applied by the SSA 310 starting with the smallest discrete attenuator (e.g., a 1 / 8 dB attenuator), then switch to a 1 / 4 dB attenuator, then activate both the 1 / 8 dB attenuator and the 1 / 4 dB attenuator to provide 3 / 8 dB attenuation, etc.

[0043] Alternatively, the controller 330 may use a successive approximation algorithm, where the controller 330 uses sequential or iterative steps to implement the best approximation change. More specifically, the controller 330 using the successive approximation algorithm involves, at each step, determining using the comparator 340 and the controller 330 whether the power level of the rectified signal is above or below a predetermined threshold, and the controller 330 iterating the attenuation applied by the SSA 310 to bring the power level of the rectified signal closer to the predetermined threshold. For example, when using the discrete attenuators shown in FIG. 3, the controller 330 using the successive approximation algorithm may first operate the discrete attenuator 310a with 16 dB of attenuation. The controller 330 may then determine, based on a comparison of the rectified signal obtained by the comparator 340 with a predetermined threshold, whether to increase the attenuation by activating the 8 dB discrete attenuator 310 b in combination with the 16 dB discrete attenuator 310 a, or decrease the attenuation by activating the 8 dB discrete attenuator 310 b without the 16 dB discrete attenuator 310 a, if additional attenuation is needed. If the controller activates the 8 dB discrete attenuator 310 b without the 16 dB discrete attenuator 310 a, the controller 330 may then determine, based on a comparison of the rectified signal obtained by the comparator 340 with a predetermined threshold, whether to increase the attenuation by activating the 4 dB discrete attenuator 310 c in combination with the 8 dB discrete attenuator 310 b, or decrease the attenuation by activating the 4 dB discrete attenuator 310 c without the 8 dB discrete attenuator 310 b, if additional attenuation is needed. In some embodiments, the successive approximation algorithm may result in attenuation that places the power level of the RF input signal within the power detection range of the rectifier 320 more quickly than the thermometer algorithm. In some embodiments, the controller 330 may be configured to control the attenuation based on a successive approximation binary search method. In this exemplary embodiment, the system 300 may, for example, set the SSA 310 to a midpoint and use the controller 330 to determine whether to increase or decrease the signal strength.In that example, it might start at 50%, determine that's low, step up to 75%, determine that's too high, set it to 62.5%, and continue iterating in this manner to arrive at a suitable adjustment amount. Other approaches could also be used, for example, a sweep method in which the adjustment starts at a value (such as zero) and increases or decreases linearly, exponentially, or otherwise until the adjusted signal falls within the power detection range of the rectifier 320. Any suitable control approach that results in adjusting the power level of the RF input as appropriate for the rectifier 320 could be implemented. In another exemplary embodiment, the comparator 340 could be a multi-level comparator (e.g., a flash ADC), and the controller 330 could receive the output from the multi-level comparator 340 and control the SSA 310 as described above. In this exemplary embodiment, the power meter output signal could be based on a combination of the rectifier output and the attenuation applied by the respective ADC output.

[0044] In an exemplary embodiment, the controller is configured to generate a plurality of digital signals for controlling the SSA, such as feedback controller 232 of Figure 2. In such an exemplary embodiment, the plurality of digital signals may be provided directly to the SSA, and more specifically, to each of the plurality of discrete attenuators, to switch each of the plurality of discrete attenuators between an on state and an off state.

[0045] In an exemplary embodiment, and referring now to FIG. 4 , a method 400 for detecting power in a radio frequency (“RF”) input signal is disclosed. Method 400 may include additional and / or a subset of the depicted and described aspects. Method 400 may be suitable for detecting power in an RF input signal over a power detector operating input power range that is wider than the rectifier operating input power range of a single rectifier used in the power detector. In an exemplary embodiment, the method includes (410) receiving an RF input signal at an SSA (such as either the SSA 110 or the SSA 310). Method 400 may further include (420) receiving at least one control signal at the SSA (e.g., from the controller 130). The at least one control signal may indicate to the SSA an amount of adjustment to apply to the RF input signal. In some embodiments, the at least one control signal may comprise a default that indicates to the SSA that no adjustment is to be made to the RF input signal during a first iteration through the power meter and / or when the RF input signal is initially received by the SSA. In some embodiments, the default value may comprise any value that indicates the initial amount of adjustment to apply to the RF input signal during the first iteration through the power meter.

[0046] The method 400 may also include adjusting (430) a signal strength of the RF input signal by an adjustment amount to produce an adjusted signal. As described above, the adjustment amount may be based on at least one control signal. In a further exemplary embodiment, the at least one control signal may be based on a comparator signal from a comparator that receives the adjusted signal.

[0047] In this exemplary embodiment, method 400 further includes rectifying (440) the conditioned signal with a single rectifier (such as rectifier 120 or rectifier 320) to generate a rectified signal.

[0048] Method 400 further includes receiving (450) the rectified signal at a controller (such as either controller 130 or 330) and generating at the controller at least one control signal based on the rectified signal. In an exemplary embodiment, the at least one control signal may be a feedback signal configured to cause the SSA to adjust the RF input signal by an adjustment amount to bring the rectified signal within a power detection range of the rectifier.

[0049] In one exemplary embodiment, the controller optionally includes a comparator for comparing the rectified signal with a predetermined threshold. As noted above, in some embodiments, the predetermined threshold may comprise one or more values ​​stored and / or retrieved from memory, from the rectifier, from a user interface, or the like. In various exemplary embodiments, the predetermined threshold is stored as part of the power meter, in local memory, on a remote server, and / or the like. In various embodiments, the predetermined threshold may be a set reference voltage level that is adjustable or permanently set, hardwired into the controller, or stored in memory. In an exemplary embodiment, the comparator generates the control signal. In another exemplary embodiment, the comparator generates a comparator output signal, which is provided to a feedback controller, which generates the control signal. The control signal may be configured to cause the SSA to adjust the power level of the RF input signal. In an exemplary embodiment, the method loops back to (420) to adjust the signal strength of the RF input signal in an iterative process by an adjustment amount controlled by the control signal. This loop can repeat until the SSA adjusts the power (attenuation or amplification) of the RF input signal sufficiently to meet a predetermined threshold (i.e., sufficiently to fall within the power detection range of the rectifier). In another exemplary embodiment, the comparator provides an input (e.g., comparator output) to the controller indicating whether the attenuated signal is within the detection range of the single rectifier, and the controller is configured to change the state of a digital-to-analog converter ("DAC") such that the SSA continues to iteratively adjust the adjustment amount until the adjusted signal is within the detection range of the single rectifier.

[0050] After the controller instructs the SSA to sufficiently adjust the power of the RF input signal, method 400 may include generating (460) at a processor (e.g., processor 180) a power detector output signal representative of the power in the RF input signal based on the rectified signal. The power detector output signal may be generated based on one or more combinations of the rectified signal and the amount of the RF input signal adjusted by the controller (e.g., at least one control signal), the rectified signal, the amount of adjustment, etc.

[0051] In one exemplary embodiment, as described above, the SSA is a variable attenuator, and adjusting the strength of the RF input signal by an adjustment amount includes adjusting the attenuation of the RF input signal through successive approximations (binary search) until the power at the output of the variable attenuator reaches a rectifier threshold.

[0052] In another exemplary embodiment, the attenuation is performed using successive approximation attenuation. In another exemplary embodiment, the SSA is a variable gain amplifier, and adjusting the strength of the RF input signal by the adjustment amount includes adjusting a gain of the RF input signal.

[0053] According to various exemplary embodiments, the power meter may be configured to report the amount of attenuation or amplification (and / or the detected input power) to a remote system, store this information in a database, or use the information for other purposes.

[0054] According to various exemplary embodiments, the ability of a single power meter to function to detect a range of different power levels allows the same power meter to be used in many different applications. Additionally, the power meter may be useful in applications where the detected RF input signal may change power levels from time to time.

[0055] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefit, advantage, solution to the problem, and any element(s) that may cause or make more pronounced any benefit, advantage, or solution are not to be construed as a critical, necessary, or essential feature or element of any or all of the claims. As used herein, "includes," "including," "comprises," "comprising," or any other variation thereof, is intended to cover a non-exclusive inclusiveness, such that a process, method, article, or apparatus comprising a list of elements does not include only those elements, but may also include other elements not expressly listed or inherent in such process, method, article, or apparatus. Furthermore, no element described herein is required for the practice of the invention unless expressly described as "essential" or "critical."

Claims

1. 1. A power meter for measuring a power level of a radio frequency (“RF”) input signal over a first input power detection range, comprising: a signal strength adjuster (SSA) that receives a radio frequency ("RF") input signal and adjusts the strength of the RF input signal by an adjustment amount in response to a control signal to generate a conditioned signal; a rectifier that rectifies the conditioned signal to generate a rectified signal, the rectifier being limited to rectify over a rectifier input power detection range that is narrower than the first input power detection range, the rectified signal, in combination with the adjustment amount, representing the detected power of the RF input signal; a controller that controls the SSA using the control signal based on the rectified signal to bring the conditioned signal within a detection range of the rectifier; A power meter comprising:

2. 2. The power meter of claim 1, wherein the first input power detection range is a power range over which the power meter can detect power in the RF input signal, the rectifier input power detection range is an operating input power range over which the rectifier can reliably detect power of a signal input to the rectifier, and the first input power detection range is at least twice the rectifier input power range.

3. 10. The power meter of claim 1, wherein the SSA is one of an attenuator or an amplifier.

4. 10. The power meter of claim 1, wherein the SSA is a variable attenuator, and wherein the power meter further comprises a digital-to-analog converter ("DAC") for receiving the control signal from the controller and providing an analog control signal to the variable attenuator that controls the amount of attenuation of the RF input signal.

5. 2. The power meter of claim 1, wherein the SSA comprises a series of discrete attenuators each configured to provide a discrete amount of attenuation, and wherein the controller controls when each of the discrete attenuators attenuates the RF input signal.

6. 10. The power meter of claim 1, wherein the SSA is a variable gain amplifier that adjusts the RF input signal based on the control signal from a digital-to-analog converter, the control signal being based on at least one signal from the controller.

7. 10. The power meter of claim 1, wherein the controller controls the attenuation based on a binary search with successive approximations method.

8. 2. The power meter of claim 1, wherein the controller is configured to generate a plurality of digital signals for controlling the SSA, the plurality of digital signals being provided to each of a plurality of discrete attenuators to switch each of the plurality of discrete attenuators between an on state and an off state.

9. 2. The power meter of claim 1, wherein the controller further comprises a comparator that compares the rectified signal with a predetermined threshold and generates a comparator signal indicative of whether the rectified signal is within the detection range of the rectifier, and wherein the control signal is based on the comparator signal.

10. 1. A wireless communication system, comprising: a power meter for measuring the power level of a radio frequency ("RF") input signal, said power meter comprising: a signal strength adjuster (SSA) that receives a radio frequency ("RF") input signal and adjusts the strength of the RF input signal by an adjustment amount in response to a control signal to generate a conditioned signal; a rectifier that rectifies the conditioned signal to generate a rectified signal that represents the detected power of the RF input signal; a controller that provides the control signal to the SSA based on the rectified signal such that the conditioned signal is within a detection range of the rectifier; A wireless communication system comprising:

11. The system of claim 10 , wherein the power meter does not include parallel-connected or cascaded rectifiers.

12. The system of claim 10 , wherein the power meter comprises a single rectifier.

13. 11. The system of claim 10, wherein the system is configured to generate a power meter output signal representative of the detected power in the RF input signal without requiring calibration for rectifier alignment or alignment of multiple rectifiers.

14. 13. The system of claim 12, wherein the operating input power range of the power meter is greater than the operating input power range of the single rectifier of the power meter.

15. 11. The system of claim 10, wherein the controller further comprises a comparator that compares the rectified signal with a predetermined threshold and generates a comparator signal indicative of whether the rectified signal is within the detection range of the rectifier, and wherein the control signal is based on the comparator signal.

16. 1. A method for detecting power in a radio frequency ("RF") input signal over a detector operating input power range greater than a rectifier operating input power range of a single rectifier used in the detector, comprising: receiving an RF input signal at a signal strength adjuster (SSA); receiving at least one control signal at the SSA; adjusting a strength of the RF input signal by an adjustment amount based on the at least one control signal to produce an adjusted signal; rectifying the conditioned signal using a single rectifier to generate a rectified signal; generating, in a controller, the at least one control signal based on the rectified signal such that the conditioned signal is within a detection range of the single rectifier; generating a power detector output signal representative of the power in the RF input signal based on the rectified signal and the amount of adjustment by the SSA; A method comprising:

17. 17. The method of claim 16, further comprising: using a comparator to compare the rectified signal with a predetermined threshold to generate a comparator signal, and wherein the at least one control signal is based on the comparator signal.

18. 17. The method of claim 16, wherein the SSA is a variable attenuator, and adjusting the strength of the RF input signal by the adjustment amount comprises adjusting the attenuation of the RF input signal through a successive approximation (binary search) method until the power at the output of the variable attenuator reaches a threshold value of the single rectifier.

19. 18. The method of claim 17, wherein the power detector output signal is based on the sum of the rectified signal and the adjustment amount, the comparator provides the comparator signal indicative of whether the attenuated signal is within the detection range of the single rectifier, and the controller is configured to change the state of a digital-to-analog converter ("DAC") such that the SSA continues to iteratively adjust the adjustment amount until the regulated signal is within the detection range of the single rectifier.

20. The method of claim 16 , wherein the damping is performed using successive approximation damping.

21. 17. The method of claim 16, wherein the SSA is a variable gain amplifier, and adjusting the power of the RF input signal by the adjustment amount comprises adjusting a gain of the RF input signal.

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