Radio system

Abstract

A radio system includes a first source of a first radio signal within a first frequency range, the first source including a first amplifier. Furthermore, the radio system includes a second source of a second radio signal within a second frequency range different from the first frequency range. The radio system is capable of transmitting the first and second radio signals to a radio receiver using a single coaxial cable and transmitting direct current (“DC”) power to power the first and second amplifiers.

Description

Technical Field

[0001] This disclosure is in the field of radio systems. Background Technology

[0002] Vehicles can be equipped with a radio system that operates using radio signals received in multiple frequency bands. To provide advantageous performance for the radio system, coaxial cables can be used to route the radio signals from the receiving antenna to the audio receiver that decodes / demodulates the signals. In cases where the vehicle's radio system operates to receive multiple radio signals in multiple frequency bands, the vehicle may include multiple coaxial cables. Because coaxial cables are complex electrical components that add weight and packaging complexity to a vehicle, reducing the number of coaxial cables required in the vehicle can be advantageous. Summary of the Invention

[0003] A radio system includes a first source of a first radio signal within a first frequency range, the first source including a first amplifier having a first amplifier output. Additionally, the radio system includes a second source of a second radio signal within a second frequency range, different from the first frequency range, the second source including a second amplifier having a second amplifier output. Furthermore, the radio system includes a first filter adapted to substantially reject the second frequency range, the first filter having a first filter input and a first filter output, the first filter input coupled to the first amplifier output. Furthermore, the radio system includes a second filter adapted to substantially reject the first frequency range, the second filter having a second filter input and a second filter output, the second filter input coupled to the second amplifier output. Furthermore, the radio system includes a first bias tee circuit having a first DC (“DC”) terminal, a first radio frequency (“RF”) terminal, and a first DC+RF terminal, the first RF terminal coupled to the first filter output and the second filter output, and a second bias tee circuit having a second DC terminal, a second RF terminal, and a second DC+RF terminal. Furthermore, the radio system includes a DC power supply coupled to power the second DC terminal. Furthermore, the radio system includes conductors coupling a first DC+RF terminal and a second DC+RF terminal, the conductors carrying a first radio signal received by a first receiver, a second radio signal received by a second receiver, and DC power from a DC power supply to power a first amplifier and a second amplifier. The first filter may be a low-pass filter adapted to substantially reject a second frequency range, and more specifically, it may be a Butterworth filter. The second filter may be a high-pass filter adapted to substantially reject the first frequency range. The first filter may include electrical components in a 0805, 0603, or 0402 package. The first filter may include at least some electrical components having a higher quality factor than at least some of the components included in the second filter.

[0004] In a radio system, the first radio signal can be an amplitude modulation / frequency modulation (“AM / FM”) signal. The first radio signal can also be an FM signal. The second radio signal can be a satellite radio signal. A satellite radio signal can be a Sirius XM (“SXM”) signal.

[0005] The radio system may also include a third filter having a third filter input and a third filter output, and a fourth filter having a fourth filter input and a fourth filter output. The third filter input may be coupled to a second RF terminal, the fourth filter input may be coupled to a second RF terminal, the third filter output may be coupled to a first receiver, and the fourth filter output may be coupled to a second receiver. The third filter may be adapted to substantially reject a second frequency range, and the fourth filter may be adapted to substantially reject a first frequency range.

[0006] The radio system may also include a first inductor-capacitor (“LC”) matching circuit disposed between the first filter output and the first RF terminal, and between the second filter output and the first RF terminal. The radio system may further include a second LC matching circuit disposed between the second RF terminal and the third filter input, and between the second RF terminal and the fourth filter input.

[0007] Furthermore, the radio system may include a voltage divider having a voltage divider input coupled to receive power from a first DC terminal, a first voltage divider output coupled to provide DC power to a first amplifier, and a second voltage divider output coupled to provide DC power to a second amplifier. The voltage divider output may have a voltage different from the voltage of the second voltage divider output.

[0008] The vehicle may include the radio system disclosed herein.

[0009] This disclosure also relates to the following technical solutions.

[0010] Option 1. A radio system, comprising:

[0011] A first source of a first radio signal, the first radio signal being within a first frequency range, the first source including a first amplifier having a first amplifier output;

[0012] A second source of a second radio signal, the second radio signal being in a second frequency range, the second frequency range being different from the first frequency range, the second source including a second amplifier having a second amplifier output;

[0013] A first filter is adapted to substantially reject the second frequency range, the first filter having a first filter input and a first filter output, the first filter input being coupled to the output of a first amplifier;

[0014] A second filter is adapted to substantially reject the first frequency range. The second filter has a second filter input and a second filter output, with the second filter input coupled to the output of a second amplifier.

[0015] A first bias tee circuit has a first DC (“DC”) terminal, a first radio frequency (“RF”) terminal and a first DC+RF terminal, the first RF terminal being coupled to a first filter output and a second filter output;

[0016] The second bias tee circuit has a second DC terminal, a second RF terminal, and a second DC+RF terminal;

[0017] A DC power supply is coupled to power the second DC terminal; and

[0018] A conductor is coupled to a first DC+RF terminal and a second DC+RF terminal, the conductor carrying a first radio signal received by a first receiver adapted to decode a first radio signal, a second radio signal received by a second receiver adapted to decode a second radio signal, and DC power from a DC power source to power a first amplifier and a second amplifier.

[0019] Option 2. The radio system according to Option 1, wherein:

[0020] The first radio signal is an amplitude / frequency ("AM / FM") radio signal; and

[0021] The second radio signal is a satellite radio signal.

[0022] Option 3. The radio system according to Option 1, wherein the first radio signal is an FM radio signal.

[0023] Option 4. The radio system according to Option 1 further includes:

[0024] A third filter with a third filter input and a third filter output; and

[0025] A fourth filter having a fourth filter input and a fourth filter output; wherein

[0026] The third filter input is coupled to the second RF terminal;

[0027] The fourth filter input is coupled to the second RF terminal;

[0028] The output of the third filter is coupled to the first receiver; and

[0029] The output of the fourth filter is coupled to the second receiver.

[0030] Option 5. The radio system according to Option 4 further includes a first LC matching circuit disposed between the first filter output and the first RF terminal and between the second filter output and the first RF terminal.

[0031] Option 6. The radio system according to Option 5 further includes a second LC matching circuit disposed between the second RF terminal and the third filter input, and between the second RF terminal and the fourth filter input.

[0032] Option 7. The radio system according to Option 1, wherein the first filter is a low-pass filter adapted to substantially reject the second frequency range.

[0033] Option 8. The radio system according to Option 7, wherein the first filter is a Butterworth filter.

[0034] Option 9. The radio system according to Option 7, wherein the second filter is a high-pass filter adapted to substantially reject the first frequency range.

[0035] Option 10. The radio system according to Option 1 further includes a voltage divider having:

[0036] The voltage divider input is coupled to receive power from the first DC terminal;

[0037] The output of the first voltage divider is coupled to provide DC power to the first amplifier; and

[0038] The output of the second voltage divider is coupled to provide DC power to the second amplifier;

[0039] The first voltage divider outputs a voltage that is different from the voltage output of the second voltage divider.

[0040] Option 11. The radio system according to Option 7, wherein the first filter includes a first electrical component, and the second filter includes a second electrical component, wherein at least some of the first electrical components have a higher quality factor than at least some of the second electrical components.

[0041] Option 12. The radio system according to Option 11, wherein at least some of the first electrical components are in a 0805, 0603 or 0402 package.

[0042] Option 13. The radio system according to Option 4, wherein the third filter is a low-pass filter adapted to substantially reject the second frequency range.

[0043] Option 14. The radio system according to Option 13, wherein the fourth filter is a high-pass filter adapted to substantially reject the first frequency range.

[0044] Option 15. The radio system according to Option 1, wherein the conductor is a coaxial cable.

[0045] Option 16. A vehicle having a radio system, the radio system comprising:

[0046] A first source of a first radio signal, the first radio signal being within a first frequency range, the first source including a first amplifier having a first amplifier output;

[0047] A second source of a second radio signal, the second radio signal being in a second frequency range, the second frequency range being different from the first frequency range, the second source including a second amplifier having a second amplifier output;

[0048] A first filter is adapted to substantially reject the second frequency range, the first filter having a first filter input and a first filter output, the first filter input being coupled to the output of a first amplifier;

[0049] A second filter is adapted to substantially reject the first frequency range. The second filter has a second filter input and a second filter output, with the second filter input coupled to the output of a second amplifier.

[0050] The first bias tee circuit has a first DC terminal, a first RF terminal and a first DC+RF terminal, wherein the first RF terminal is coupled to the output of the first filter and the output of the second filter.

[0051] The second bias tee circuit has a second DC terminal, a second RF terminal, and a second DC+RF terminal;

[0052] A DC power supply is coupled to power a second DC terminal; and

[0053] A conductor is coupled to a first DC+RF terminal and a second DC+RF terminal, the conductor carrying a first radio signal received by a first receiver adapted to decode a first radio signal, a second radio signal received by a second receiver adapted to decode a second radio signal, and DC power from a DC power source to power a first amplifier and a second amplifier.

[0054] Option 17. The vehicle according to Option 16, wherein the first radio signal is an AM / FM radio signal.

[0055] Option 18. The vehicle according to Option 17, wherein the second radio signal is a gigahertz radio signal.

[0056] Option 19. The vehicle according to Option 18, wherein the second radio signal is a satellite radio signal.

[0057] Option 20. A radio system comprising:

[0058] A first source of a first radio signal, the first radio signal being within a first frequency range, the first source including a first amplifier having a first amplifier output;

[0059] A second source of a second radio signal, the second radio signal being in a second frequency range, the second frequency range being different from the first frequency range, the second source including a second amplifier having a second amplifier output;

[0060] A first filter is adapted to substantially reject the second frequency range, the first filter having a first filter input and a first filter output, the first filter input being coupled to the output of a first amplifier;

[0061] A second filter is adapted to substantially reject the first frequency range. The second filter has a second filter input and a second filter output, with the second filter input coupled to the output of a second amplifier.

[0062] The first bias tee circuit has a first DC terminal, a first RF terminal and a first DC+RF terminal, wherein the first RF terminal is coupled to the output of the first filter and the output of the second filter.

[0063] The second bias tee circuit has a second DC terminal, a second RF terminal, and a second DC+RF terminal;

[0064] A third filter has a third filter input and a third filter output, and is adapted to substantially reject the second frequency range. The third filter input is coupled to a second RF terminal, and the third filter output is coupled to a first radio receiver adapted to decode the first radio signal.

[0065] A fourth filter, having a fourth filter input and a fourth filter output, and adapted to substantially reject a first frequency range, the fourth filter input being coupled to a second RF terminal, and the fourth filter output being coupled to a second radio receiver adapted to decode a second radio signal;

[0066] A DC power supply is coupled to provide DC power to a second DC terminal; and

[0067] A coaxial cable is coupled to a first DC+RF terminal and a second DC+RF terminal. The coaxial cable carries a first radio signal received by a first receiver, a second radio signal received by a second receiver, and DC power from a DC power source to power a first amplifier and a second amplifier.

[0068] The above summary does not represent every embodiment or aspect of this disclosure. The features and advantages pointed out above, as well as other possible features and advantages, will readily become apparent from the following detailed description of embodiments and preferred modes of practice of this disclosure when considered in conjunction with the accompanying drawings and appended claims. Furthermore, this disclosure explicitly includes combinations and sub-combinations of the elements and features presented above and below. Attached Figure Description

[0069] Figure 1 The illustration shows a vehicle equipped with a radio system.

[0070] Figure 2 yes Figure 1 A block diagram of the vehicle's radio system.

[0071] Figure 3 The diagram shows... Figure 2 The biased three-way circuit.

[0072] Figure 4 yes Figure 2 Block diagram of a voltage divider.

[0073] Figure 5 The diagram shows... Figure 2 The circuit system of filters and matching circuits. Detailed Implementation

[0074] First refer to Figure 1 The illustration depicts vehicle 100. Vehicle 100 can be any type of vehicle, such as a car, truck, van, SUV, motorcycle, boat, or aircraft. Vehicle 100 can be equipped with a radio system suitable for receiving radio signals in multiple frequency bands. Such frequency bands may include amplitude modulation (“AM”), which can operate at frequencies between approximately 540 kHz (“KHz”) and approximately 1700 kHz; frequency modulation (“FM”), which can operate at frequencies between approximately 88 MHz (“MHz”) and approximately 108 MHz; and satellite radio, which can operate at frequencies in the gigahertz (“GHz”) range (that is, they are “gigahertz radio signals”) and can operate in the range between approximately 2 GHz and approximately 4 GHz. A satellite radio service provider operates under the trademark Sirius XM (which may be referred to as “SXM” below in this disclosure) and operates in the range of 2.320 GHz to 2.345 GHz.

[0075] Vehicle 100 may have multiple antennas for receiving signals from various radio frequency bands that the vehicle 100's radio system can receive. For example, antenna 102 may be an AM radio antenna, with a geometry suitable for receiving AM radio signals. Additionally, antenna 104 may be an FM radio antenna, particularly suitable for receiving FM radio signals. Furthermore, antenna 106 may be a satellite radio antenna, particularly suitable for receiving satellite radio signals. Antennas 102, 104, and 106 may be fed to tuner antenna module 108. Tuner antenna module 108 may be located near antennas 102, 104, and 106, near the roof of vehicle 100, and possibly within the ceiling of vehicle 100. The proximity of the antennas to tuner antenna module 108 allows signals from the antennas to be locally filtered and amplified. This local processing helps provide strong, low-noise signals for routing signals through vehicle 100 while maintaining a favorable high signal-to-noise ratio. One or more antennas may also be combined to form a multi-band antenna suitable for receiving, for example, AM and FM signals. Furthermore, signals from antenna 102 (AM antenna) and antenna 104 (FM antenna) can be combined to provide a combined AM / FM signal. This combined AM / FM signal can have a cascaded frequency range representing the AM and FM frequency ranges, from approximately 540 kHz (at the low end) to approximately 108 MHz (at the high end).

[0076] Based on the foregoing discussion, AM / FM signals and SXM signals can be considered to be in different (i.e., non-overlapping) frequency ranges. Similarly, AM signals and SXM signals can be considered to be in different frequency ranges, as can FM signals and SXM signals.

[0077] Signals from antennas 102, 104, and 106 exiting tuner antenna module 108 can be routed to central control unit 112 via conductor 110 (such as a coaxial cable). Central control unit 112 may include a radio receiver unit, module, or circuitry for decoding AM, FM, and satellite radio signals used by the audio system in vehicle 100, for example, for playing the decoded / demodulated content through audio speakers in vehicle 100. Central control unit 112 may also include electronics for performing additional and various functions within vehicle 100. Conductor 110 may have a length suitable for connecting tuner antenna module 108 to central control unit 112. Depending on the geometry of vehicle 100, this length can range from 2.5 to 5 meters.

[0078] Now for reference Figure 2The tuner antenna module 108 may include an AM / FM front-end module (“FEM”) 120 and an SXM front-end module (“FEM”) 122. The AM / FM FEM 120 may include a filter 124. The filter 124 may be adapted to reject out-of-band noise in the AM / FM signal. The AM / FM FEM 120 may also include an amplifier 126. The amplifier 126 amplifies the AM / FM signal to help provide a strong, low-noise signal for routing through vehicle 100 while maintaining a favorable high signal-to-noise ratio. The amplifier 126 may be a so-called low-noise amplifier (“LNA”), which is particularly suitable for amplifying signals in environments where noise is particularly unfavorable. Generally, a low-noise amplifier is an electronic component that amplifies very low-power signals without significantly degrading their signal-to-noise ratio. The amplifier 126 may also be implemented by multiple amplifiers arranged in series.

[0079] The AM / FM FEM 120 can also be replaced by an FEM that includes only FM or an FEM that includes only AM.

[0080] The SXM FEM 122 may include a filter 128 adapted to reject out-of-band noise in the SXM signal. The SXM FEM 122 may also include an amplifier 130. The amplifier 130 amplifies the SXM signal to help provide a strong, low-noise signal for routing through vehicle 100 while maintaining a favorable high signal-to-noise ratio. The amplifier 130 may be a so-called low-noise amplifier (“LNA”), which is particularly suitable for amplifying signals in environments where noise is particularly unfavorable. Generally, a low-noise amplifier is an electronic component that amplifies very low-power signals without significantly degrading their signal-to-noise ratio. The amplifier 130 may also be implemented by multiple amplifiers arranged in series.

[0081] FEM can be considered as the source of the corresponding radio signals output from FEM.

[0082] The output of AM / FM FEM 120 can be coupled to input 140 of filter 142; filter 142 can also have output 144. The output of SXM FEM 122 can be coupled to input 146 of filter 148; filter 148 can also have output 150.

[0083] The outputs 144 of filter 142 and 150 of filter 148 can be coupled to a matching circuit 154 having an output 155. The output 155 of the matching circuit 154 can then be coupled to the RF terminal 156 of the bias tee circuit 158.

[0084] Now, additional references Figure 3Additional details regarding the bias tee circuit 158 ​​are provided below. As discussed above, the bias tee circuit 158 ​​can be a circuit system that may have an RF terminal 156. The bias tee circuit 158 ​​may also have a DC terminal 160. Furthermore, the bias tee circuit 158 ​​may have a DC+RF terminal 162. The bias tee circuit 158 ​​may also include a capacitor 164 and an inductor 165. The capacitor 164 may be a combination of multiple capacitors (e.g., in parallel), and the inductor 165 may be a combination of multiple inductors (e.g., in series) to be effective at multiple frequencies. The bias tee circuit 158 ​​can be designed, and the sizes of the capacitor 164 and the inductor 165 can be determined to allow DC bias of the RF signal.

[0085] Refer again Figure 2 The DC terminal 160 of the bias tee circuit 158 ​​can be coupled to the voltage divider 166. The voltage divider 166 can provide DC power to the power amplifier 126 via output 168 and to the power amplifier 130 via output 170. Each of the amplifiers 126 and 130 can be an active amplifier and therefore may require a source of DC power.

[0086] Now, additional references Figure 4 Additional details are provided for voltage divider 166. Voltage divider 166 can be adapted to provide two different output voltages to output 168 and output 170. Voltage divider 166 may include an RF filter 172. With the associated amplifier (here, amplifier 126) operating at the voltage provided at input 167, the output of RF filter 172 can be directly provided to the output of voltage divider 166. The output of RF filter 172 can also be provided to DC / DC converter 173, which can be a "buck" topology, which can be useful for voltage reduction. The output of DC / DC converter 173 can be provided to an additional RF filter 174 to filter out electrical noise that may have been introduced by DC / DC converter 173. The output of RF filter 174 can be provided to low dropout ("LDO") voltage regulator 176, and the output of LDO voltage regulator 176 is provided to output 170 of voltage divider 166. Note that the voltage at output 170 of voltage divider 166 may be less than the voltage at output 168 of voltage divider 166. If the required voltage reduction is limited, the DC / DC converter 173 can be omitted, and the LDO voltage regulator 176 can be used simply.

[0087] If amplifiers 126 and 130 are powered by equal DC voltages, voltage divider 166 can be omitted; in this case, the “DC” terminal 160 of bias tee circuit 158 ​​can be coupled to power both amplifiers 126 and 130, possibly via an RF filter if necessary.

[0088] The DC+RF terminal 162 of the bias tee circuit 158 ​​can be coupled to conductor 110. Conductor 110 can be a coaxial cable with an internal signal conductor surrounded by an electrical noise protection shield.

[0089] Now, additional references Figure 5 Filter 142 can be a low-pass filter. Filter 142 can additionally be a Butterworth filter consisting of inductor 182 and capacitor 184. As a low-pass filter, filter 142 can be adapted to pass relatively lower frequencies of AM / FM, but reject, substantially reject, or filter out relatively higher frequencies of SXM. Inductor 182 and capacitor 184 can be selected to have a desired frequency cutoff point for filter 142. Filter 142 can be designed with a simple or complex topology, as long as it is suitable for providing filtering characteristics (frequency cutoff point, roll-off steepness of its frequency response) that are desired to pass AM / FM frequencies but appropriately reject or substantially reject SXM frequencies. A simpler topology can provide the benefits of fewer components and lower power losses. Given a relatively large frequency separation between the AM / FM and SXM bands, a relatively simple Butterworth filter topology with a moderate slope of its frequency response roll-off may be suitable for filter 142.

[0090] The frequency breakpoint of filter 142—which is sometimes referred to as its “cutoff” or “knee” frequency—can be selected to be above the upper end of the AM / FM frequency range (e.g., above 108 MHz) but below the lower end of the satellite radio frequency range (e.g., below 2 GHz or 2.3 GHz). The frequency breakpoint can be a frequency that filter 142 has... Or the frequency of –3dB voltage gain. The frequency breakpoint can be the boundary between the passband (below the frequency breakpoint, where the filter 142 can be considered to pass primarily through the frequency components applied to the filter 142) and the stopband (above the frequency breakpoint, where the filter 142 can be considered to primarily stop, block, or filter out the frequency components applied to the filter 142) of the filter 142.

[0091] Filter 148 can be a high-pass filter. Filter 148 can additionally be a Butterworth filter including capacitor 186 and inductor 188. As a high-pass filter, filter 148 can be adapted to pass relatively higher frequencies of SXM, but reject, substantially reject, or filter out relatively lower frequencies of AM / FM. Capacitor 186 and inductor 188 can be selected to have a desired frequency cutoff point for filter 148. Filter 148 can be designed with a simple or complex topology, as long as it is suitable for providing filtering characteristics (frequency cutoff point, roll-off steepness) that are desired to pass SXM frequencies but appropriately reject AM / FM frequencies. A simpler topology can provide the benefits of fewer components and lower power loss. Given a relatively large frequency separation between the AM / FM and SXM bands, a relatively simple Butterworth filter topology with a moderate slope of its frequency response roll-off may be suitable for filter 148.

[0092] The frequency breakpoint of filter 148 can be selected to be above the upper end of the AM / FM frequency range (e.g., above 108 MHz) but below the lower end of the satellite radio frequency range (e.g., below 2 GHz or 2.3 GHz). The frequency breakpoint can be a feature of filter 148. Or the frequency of –3dB voltage gain. The frequency breakpoint can be the boundary between the passband of filter 148 (above the frequency breakpoint, where filter 148 can be considered to pass primarily through the frequency components applied to filter 142) and the stopband of filter 148 (below the frequency breakpoint, where filter 148 can be considered to primarily stop, block, or filter out the frequency components applied to filter 148).

[0093] Filter 148 may include relatively small capacitors 186 and inductors 188. These may be chip-based or surface-mount and may be in a so-called "0201" package or printed components. Due to the lower frequency of AM / FM signals relative to SXM signals, filter 142 may include larger inductors and capacitors. Filter 142 may employ high-Q (i.e., "high quality factor") inductors and capacitors with reduced power loss for better efficiency. High-Q components may be larger than other components, and their use in this system may be counterintuitive in other ways, but they may be suitable for use in the low-frequency environment of filter 142. Inductors 182 and capacitors 184 may be in so-called "0805," "0603," or "0402" packages. Some or all of inductors 182 may have a higher Q factor than some or all of inductors 188. Furthermore, some or all of capacitors 184 may have a higher Q factor than some or all of capacitors 186.

[0094] The “0805” package can be approximately 2.0 mm (length) x 1.2 mm (width). The “0603” package can be approximately 1.55 mm (length) x 0.85 mm (width). The “0402” package can be approximately 1.0 mm (length) x 0.5 mm (width). The “0201” package can be approximately 0.6 mm (length) x 0.3 mm (width).

[0095] Matching circuit 154 may be a circuit (i.e., an "LC" circuit) comprising inductors and capacitors suitable for use as matching filters or tuning filters, wherein inductor 190 and capacitor 192 (or a combination of inductors and capacitors) are selected to be suitable for tuning the circuit. Matching circuit 154 may be designed to reduce signal reflections. Matching circuit 154 may have an output 155. Matching circuit 154 may use larger "0805", "0603", or "0402" capacitors and inductors, and may be high-Q or relatively high-Q components.

[0096] Refer again Figure 2 The central control unit 112 includes an AM / FM receiver module 200 adapted to decode / demodulate AM / FM signals received by antennas 104 and 106 and provide the decoded / demodulated signals as auditory output, for example, from the audio system of vehicle 100. The central control unit 112 also includes an SXM receiver module 202 adapted to decode / demodulate SXM signals received by antenna 102 and provide the decoded / demodulated signals as auditory output, for example, from the audio system of vehicle 100.

[0097] It should be noted that the radio system described herein can be constructed in various alternative ways without departing from the spirit of this disclosure. For example, the AM / FM receiver module 200 can be integrated with the SXM receiver module 202. Alternatively, the AM / FM receiver module 200 may include separate modules for AM and FM reception. Therefore, when "SXM receiver" is mentioned in this disclosure, such reference should be interpreted as meaning a device suitable for decoding / demodulating SXM signals, whether such receiver is standalone or integrated with other electronic equipment. The references to "AM / FM receiver," "AM receiver," and "FM receiver" also apply.

[0098] Conductor 110 can be coupled to the DC+RF terminal 204 of the bias tee circuit 206. (Note that the topology of the bias tee circuit 206 can be similar to or the same as that of the bias tee circuit 158). The DC terminal 208 of the bias tee circuit 206 can be coupled to a DC power supply 210. For example, the DC power supply 210 can be a 12-volt, 5-volt, 8.5-volt, or other suitable DC power supply for powering amplifiers 126 and 130.

[0099] The RF terminal 212 of the bias tee circuit 206 can be coupled to the matching circuit 214. The matching circuit 214 can have a similar topology to the matching circuit 154 and can be designed with similar or the same design considerations as the matching circuit 154.

[0100] The output 215 of matching circuit 214 can be coupled to the input 216 of filter 218; filter 218 can also have an output 220. Filter 218 can be a low-pass filter, designed to appropriately pass relatively low AM / FM frequencies and appropriately reject, substantially reject, or filter out relatively high SXM frequencies. Filter 218 can be similar to or the same as filter 142, and similar design considerations can be applied. Filter 218 can be a Butterworth filter, a relatively simple filter that can be used when there is a relatively large separation between the given AM / FM and SXM frequency bands.

[0101] The output 215 of matching circuit 214 can also be coupled to input 222 of filter 224; filter 224 can also have output 226. Filter 224 can be a high-pass filter, designed to appropriately pass relatively high SXM frequencies and appropriately reject, substantially reject, or filter out relatively low AM / FM frequencies. Filter 224 can be similar to or the same as filter 148, and similar design considerations can be applied. Filter 218 can be a Butterworth filter, a relatively simple filter that can be used when there is a relatively large separation between a given AM / FM band and a satellite radio (e.g., SXM) band.

[0102] Alternatively, an RF switch can be provided that alternately couples the output 212 of the bias tee circuit 206 to receiver module 200 and receiver module 202.

[0103] This disclosure allows for numerous different embodiments. Representative examples of this disclosure are shown in the accompanying drawings and are described in detail herein as non-limiting examples of the disclosed principles. Therefore, elements and limitations described in the abstract, introduction, summary, and detailed description sections but not expressly set forth in the claims should not be incorporated into the claims, individually or collectively, by implication, inference, or otherwise.

[0104] For the purposes of this specification, unless otherwise stated, the use of the singular includes the plural, and vice versa; the terms “and” and “or” should be both conjunctions and disjunctive words; “any” and “all” should mean “any and all”; and the words “including,” “contains,” “including,” “having,” etc., should mean “included without limitation.” Furthermore, approximate words such as “approximately,” “almost,” “substantially,” “generally,” “approximately,” etc., may be used herein in the sense of “being, near, or almost being” or “within its 0-5%” or “within acceptable manufacturing tolerances” or logical combinations thereof.

Claims

1. A radio system comprising: A first source of a first radio signal, the first radio signal being within a first frequency range, the first source including a first amplifier having a first amplifier output; A second source of a second radio signal, the second radio signal being in a second frequency range, the second frequency range being different from the first frequency range, the second source including a second amplifier having a second amplifier output; A first filter is adapted to substantially reject the second frequency range, the first filter having a first filter input and a first filter output, the first filter input being coupled to the output of a first amplifier; A second filter is adapted to substantially reject the first frequency range. The second filter has a second filter input and a second filter output, with the second filter input coupled to the output of a second amplifier. A first bias tee circuit has a first DC terminal, a first RF terminal and a first DC+RF terminal, wherein the first RF terminal is coupled to the output of a first filter and the output of a second filter. The second bias tee circuit has a second DC terminal, a second RF terminal, and a second DC+RF terminal; The DC power supply is coupled to supply power to the second DC terminal; and A conductor is coupled to a first DC+RF terminal and a second DC+RF terminal, the conductor carrying a first radio signal received by a first receiver adapted to decode a first radio signal, a second radio signal received by a second receiver adapted to decode a second radio signal, and DC power from a DC power source to power a first amplifier and a second amplifier.

2. The radio system according to claim 1, wherein: The first radio signal is an amplitude / frequency modulation ("AM / FM") radio signal; and The second radio signal is a satellite radio signal.

3. The radio system of claim 1, further comprising: A third filter with a third filter input and a third filter output; and A fourth filter with a fourth filter input and a fourth filter output; in The third filter input is coupled to the second RF terminal; The fourth filter input is coupled to the second RF terminal; The output of the third filter is coupled to the first receiver; and The output of the fourth filter is coupled to the second receiver.

4. The radio system of claim 3, further comprising a first LC matching circuit disposed between the first filter output and the first RF terminal and between the second filter output and the first RF terminal.

5. The radio system of claim 1, wherein, The first filter is a low-pass filter, which is suitable for essentially rejecting the second frequency range.

6. The radio system of claim 5, wherein, The second filter is a high-pass filter, suitable for essentially rejecting the first frequency range.

7. The radio system of claim 1, further comprising a voltage divider having: The voltage divider input is coupled to receive power from the first DC terminal; The output of the first voltage divider is coupled to provide DC power to the first amplifier; and The output of the second voltage divider is coupled to provide DC power to the second amplifier; The first voltage divider outputs a voltage that is different from the voltage output of the second voltage divider.

8. The radio system of claim 5, wherein, The first filter includes first electrical components, and the second filter includes second electrical components, at least some of the first electrical components having a higher quality factor than at least some of the second electrical components.

9. The radio system of claim 8, wherein, At least some of the first electrical components are in an 0805, 0603, or 0402 package.

10. The radio system of claim 1, wherein, The conductor is a coaxial cable.

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