MULTI-TUNE FILTER AND CONTROL THEREFOR
20230361745 · 2023-11-09
Inventors
Cpc classification
H03H7/12
ELECTRICITY
International classification
Abstract
A multi-tune filter system and a control system for operating the multi-tune filter system are described herein. The multi-tune filter system is a tunable frequency range filter. Further, the multi-tune filter system is a digitally programmable filter with an adjustable passband between first and second customizable frequency bounds f1, f2.
Claims
1. A multi-tune filter system, the filter system having a frequency range filter having a filter topology comprising: a first frequency and a second frequency, where the first frequency is lower than the second frequency; and a third frequency which is greater than the first frequency and lesser than the second frequency, wherein each of the first frequency and the second frequency are selected from the range consisting of 1.5 MHz to 30 Mhz, and wherein the third frequency is equal to one half the sum of the first frequency and the second frequency, and at least one elliptic Cauer-Chebyshev topology implemented with a minimum of two capacitors.
2. (canceled)
3. The multi-tune filter system of claim 1, wherein the first, second, and third frequencies are variable in 100 KHz increments.
4. The multi-tune filter system of claim 1, further comprising a low pass filter topology and a high pass filter topology.
5. The multi-tune filter system of claim 4, wherein the low pass filter topology comprises first, second, and third digital low pass filter legs.
6. The multi-tune filter system of claim 5, wherein the high pass filter topology comprises first, second, and third digital high pass filter legs.
7. The multi-tune filter system of claim 6, wherein at least one of the first, second, and third digital low pass filter legs and at least one of the first, second, and third, digital high pass filter legs are variable and dependent on the third frequency.
8. A method of controlling a multi-tune filter, comprising: selecting a center frequency; setting first and second frequency values equidistant from the center frequency, manipulating a plurality of impedance transformers and a plurality of radio frequency switches, wherein manipulation of the plurality of impedance transformers and plurality of radio frequency switches adjust the first and second frequency values.
9. The method of controlling the multi-tune filter of claim 8, wherein the plurality of impedance transformers and plurality of radio frequency switches are manipulated to change a digital signal.
10. The method of controlling the multi-tune filter of claim 9, wherein the first and second frequency values are respectively determined by a high pass filter leg and a low pass filter leg of the multi-tune filter.
11. (canceled)
12. The method of controlling the multi-tune filter of claim 10, wherein the first and second frequency values correspond to a plurality of impedances, the plurality of impedances derived from the low pass filter leg and the high pass filter leg respectively.
13. The method of controlling the multi-tune filter of claim 12, wherein each of the high pass filter leg and the low pass filter leg comprise nine frequency subranges.
14. A multi-tune filter control system, comprising: a first frequency limit at 1.5 MHz and a second frequency limit at 30 MHz; a first frequency and a second frequency, each of the first and second frequencies being selected within a frequency range defined by the first and second frequency limits; a center frequency between the first and second frequencies; an adjustable passband filter implemented between the first and second frequencies; wherein the first and second frequencies are adjustable through manipulation of the plurality of impedance transformers and plurality of radio frequency switches, and the filter control system further manipulates at least one elliptic Cauer-Chebyshev topology implemented with a minimum of two capacitors.
15. The multi-tune filter control system of claim 14, wherein the first frequency is derived from a plurality of low pass filters and the second frequency is derived from a plurality of high pass filters.
16. The multi-tune filter control system of claim 15, wherein a first digital control signal manipulates the plurality of low pass filters and a second digital control signal manipulates the plurality of high pass filters, and wherein the first and second digital control signals represent the selected first and second frequencies.
17. The multi-tune filter control system of claim 16, wherein one or more of the plurality of low pass filters and one or more of the plurality of high pass filters act on an incoming signal to implement the first frequency bound, the second frequency bound, and the center frequency, transforming the incoming signal to a filtered signal.
18. (canceled)
19. (canceled)
20. The multi-tune filter control system of claim 17, wherein the plurality of low pass filters and the plurality of high pass filters are digitally tuned to implement a center frequency equidistant from each of the first and second frequencies.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings, which are included to provide further understanding and are incorporated in and constitute a part of this specification, illustrate disclosed embodiments and together with the description serve to explain the principles of the disclosed embodiments. In the drawings:
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[0039] In one or more implementations, not all of the depicted components in each figure may be required, and one or more implementations may include additional components not shown in a figure. Variations in the arrangement and type of the components may be made without departing from the scope of the subject disclosure. Additional components, different components, or fewer components may be utilized within the scope of the subject disclosure.
DETAILED DESCRIPTION
[0040] The detailed description set forth below is intended as a description of various implementations and is not intended to represent the only implementations in which the subject technology may be practiced. As those skilled in the art would realize, the described implementations may be modified in various different ways, all without departing from the scope of the present disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive.
I. General Overview
[0041] Generally, the present disclosure details, with reference to
[0042] The first and second customizable frequency bounds f1, f2 are independently tuned to desired frequencies above and below a center frequency fc. The first and second customizable frequency bounds f1, f2 define the range limits of a tuned pass band/frequency range filter implemented by the multi-tune filter system 100.
II. Example Implementations
[0043] Apparatus
[0044] Referring now to
[0045] Referring back to
[0046] Typically, as the cutoff frequency is tuned away from a nominal value, performance of an elliptic filter may decrease, higher flyback in the attenuation range of the filter may be produced, matching from the nominal input/output impedance (e.g., 50 ohm) may worsen, and higher insertion loss at the passband may occur. To address these characteristics, the multi-tune filter system 100 utilizes multi-aperture core wideband impedance transformers T2, T3 to facilitate tuning. The impedance transformers T2, T3 adjust the input/output impedance of each of the first, second, and third high pass filter legs 120, 122, 124 from a nominal level to a higher or lower level depending on a desired cutoff frequency.
[0047] To implement lower cutoff frequencies, the impedance transformers T2, T3 adjust each high pass filter leg 120, 122, 124, as needed, from nominal 50 ohms to 35 ohms. To implement higher cutoff frequencies, the impedance transformers adjust each high pass filter leg 120, 122, 124, as needed, from nominal 50 ohms to 70 ohms. In the example architecture of
[0048] In
[0049] As analogously detailed with respect to the topology of
[0050] To implement lower cutoff frequencies, the impedance transformer T1 adjusts each low pass filter leg 126, 128, 130, as needed, from nominal 50 ohms to 35 ohms. To implement higher cutoff frequencies, the impedance transformer T1 adjusts each low pass filter leg 126, 128, 130, as needed, from nominal 50 ohms to 70 ohms. In the example architecture of
[0051] An exemplary embodiment of the multi-tune filter system 100 is controlled through a serial peripheral interface. The multi-tune filter system 100 may be commanded by two words (e.g., 16 bits each word) to set the adjustable passband 104. In examples, the two words define the first and second customizable frequency bounds f1, f2. The customizable frequency bounds f1, f2 are defined with 100 KHz resolution (e.g. a step size between selectable frequencies for f1 and f2 is 100 KHz, as also illustrated in
[0052] In exemplary embodiments, the second customizable frequency bound f2 must be greater than f1. In other words, the upper bound of the frequency range is greater than the lower bound thereof. Referring again to the table of
[0053] In certain embodiments, when the multi-tune filter system 100 is commanded to tune the first and second customizable frequency bounds f1, f2 between step sizes, then the customizable frequencies may be automatically tuned to nearest rounded frequencies corresponding to the 71 discrete channels shown in
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[0057] The low pass address set command 140 and the high pass address set command 142 will set the respective customizable frequency bounds f1, f2 when an address in the range of “0000 1111” to “1 0010 1100” (corresponding to 15-300 decimal, as noted hereinabove) is clocked into the multi-tune filter system 100. Tuning of the multi-tune filter system 100 may be performed in about 50 vs.
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[0061] For the multi-tune filter system 100 shown and described with respect to
[0062] Control Methods
[0063] The control 102 for the multi-tune filter system 100 is shown and described with reference to
[0064] The low and high pass address set commands 140, 142 have corresponding enablement check steps 146 that check a setting of a tune enable status register 202 (refer ahead to
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[0066] Similarly, along branch 152, the decoder 108 receives a request to execute the high pass address set command 142. Accordingly, a high pass status register 206 and the tune enable status register 202 are set to enable setting of the high pass customizable frequency bound f2. In read unit, branches 154, 156, 158 the tune enable status register 202 is disabled to prevent setting of either of the customizable frequency bounds f1, f2. The read unit branches 154, 156, 158 perform one or more of variations on the serial out command 144 (see also
[0067]
[0068] Referring now to
[0069] Control branch 162 (C-A-B-C) performs the steps for read unit functions (as further described with respect to
[0070] If initialization has already been performed then the data processor moves to control branches 164, 166, whereby the data processor 106 performs the low and high pass address set commands 140, 142 and the serial data out command 144, respectively. At decision block 168, the data processor 106 checks whether an incoming instruction is one of the low and high pass address set commands 140, 142 or the serial data out command 144.
[0071] The first control branch 164 (C-D-E-C or C-D-F-C) executes the low and high pass address set commands 140, 142. At step 170, a serial data out register is locked during first control branch 164. Then at step 172, a system tune ready initialization is set, followed by setting the tune enable status register 202 to “on” thereby preparing the multi-tune filter system 100 to receive a customizable frequency bound setting. At step 174, the data processor 106 sends a read command to memory control, and at step 176 an address within memory to be read is transmitted to the memory control. The memory control returns the contents of the memory location to a temporary storage register for storing the customizable frequency bound f1, f2 during either the low or high pass address set commands 140, 142. Step 178 detects a selection of which customizable frequency bound f1, f2 is being set.
[0072] At decision step 180 along the control branch 164, a low pass enable status register 212 is checked. Alternatively, a high pass enable status register could be checked; however, only one of the two status registers (i.e., low pass enable or high pass enable) need be checked to determine whether the command to be performed is the low pass address set command 140 or the high pass address set command 142. In the present example, if the low pass enable status register 212 is enabled (“YES”) at the decision step 180, then the low pass command 140 is executed (D-E-C) to set the first customizable frequency bound f1. But, if the low pass enable status register 212 is not enabled (“NO”) at the decision step 180, then the high pass command 142 is executed (D-F-C) to set the second customizable frequency bound f2.
[0073] The second control branch 166 (C-G-C) executes the serial data out command 144 and the read unit functions. First, at step 182, the tune enable status register 202 is disabled because during the serial data out command 144, bytes received from the serial data processor 118 are not stored as the customizable frequency bounds f1, f2. Instead, memory units accessed during execution of the second control branch 166 are only read and not written.
[0074] Referring again to
[0075] The status registers described hereinthroughout may instead be bits of an instruction received by the serial data processor 118. Received instructions may be temporarily, permanently, and/or semi-permanently stored in one or more volatile or non-volatile memory modules (e.g., random access memory (SRAM), flash memory, and electrically erasable programmable read-only memory (EEPROM)). The present disclosure contemplates that the control algorithm(s) 102 and the multi-tune filter system 100 may be integrated with an embedded microcontroller comprising one or more suitable processing modules and one or more memory modules (e.g., the processors 106, 118 and the memory 110) for storing the customizable frequency bounds f1, f2 and other parameters defining the adjustable passband 104. Also, in examples, one or more memory modules may instead be disposed remotely, such as in cloud storage and/or on a server, and accessible by the one or more processing modules through one or more wired and/or wireless connections. For example, the processors 106, 118 and the memory 110 may be configured as part of a communications device or as a separate control module associated only with the multi-tune filter 100. Also, example embodiments may integrate the processors, 106, 118, the memory 110, and the other control components as a single control module. Alternatively, these processing components may be separate, but communicatively coupled.
[0076] The embodiment(s) detailed hereinabove may be combined in full or in part, with any alternative embodiment(s) described.
INDUSTRIAL APPLICABILITY
[0077] The disclosed systems and methods can be implemented with an electronics system, using, for example, software, hardware (e.g., passive and/or active electronic components), and/or a combination of both, either with a dedicated microcontroller, integrated into another entity (e.g., communications device), or distributed across multiple entities. An exemplary system includes a bus or other communication mechanism for communicating information, and a processor coupled with the bus for processing information. The processor may be locally or remotely coupled with the bus. By way of example, the filter system may be implemented with one or more processors. The processor may be a general-purpose microprocessor, a microcontroller, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a controller, a state machine, gated logic, discrete hardware components, or any other suitable entity that can perform calculations or other manipulations of information. The filter system also includes a memory, such as a Random-Access Memory (RAM), a flash memory, a Read Only Memory (ROM), a Programmable Read-Only Memory (PROM), an Erasable PROM (EPROM), registers, a hard disk, a removable disk, a CD-ROM, a DVD, or any other suitable storage device, coupled to a bus for storing information and instructions to be executed by processor.
[0078] According to one aspect of the present disclosure, the disclosed system can be implemented using a number of active and/or passive electronic components in response to a processor executing one or more sequences of one or more instructions contained in memory. Such instructions may be read into memory from another machine-readable medium, such as a data storage device. Execution of the sequences of instructions contained in main memory causes the processor to perform the process steps described herein. One or more processors in a multi-processing arrangement may also be employed to execute the sequences of instructions contained in memory. In alternative implementations, hard-wired circuitry may be used in place of or in combination with software instructions to implement various implementations of the present disclosure. Thus, implementations of the present disclosure are not limited to any specific combination of hardware circuitry and software. According to one aspect of the disclosure, the disclosed system can be implemented using one or many remote elements in an electronics system (e.g., cloud computing), such as a processor that is remote from other elements of the exemplary filter system described above.
[0079] A reference to an element in the singular is not intended to mean “one and only one” unless specifically stated, but rather “one or more.” The term “some” refers to one or more. Underlined and/or italicized headings and subheadings are used for convenience only, do not limit the subject technology, and are not referred to in connection with the interpretation of the description of the subject technology. Relational terms such as first and second and the like may be used to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. All structural and functional equivalents to the elements of the various configurations described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and intended to be encompassed by the subject technology. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the above description.
[0080] Numerous modifications to the present disclosure will be apparent to those skilled in the art in view of the foregoing description. Preferred embodiments of this disclosure are described herein, including the best mode known to the inventors for carrying out the disclosure. It should be understood that the illustrated embodiments are exemplary only and should not be taken as limiting the scope of the disclosure.