Tunable broadband distribution circuit

Abstract

Tunable broadband distribution circuit (300, 460) for transmitting a signal in a selected frequency band chosen from a plurality of frequency bands over a transmission line (302, 304) of a physical length, wherein the tunable broadband distribution circuit (300, 460) comprises: a plurality of switches (406, 408) configured to select from among a plurality of local oscillators (402, 404) to select frequency band 10, wherein the plurality of local oscillators (402, 404) are configured to provide signals in the plurality of frequency bands; a gain buffer (104) configured to amplify the signal and output the amplified signal to the transmission line, wherein the gain of the gain buffer (104) can be specified at least based on the selected frequency band of the signal; and a tuning element (306) configured to modify an effective length of the transmission line (302, 304) by varying an amount of the impedance in series with the transmission line at least on the basis of the selected frequency band of the signal, wherein the tuning element (306) is electrically coupled to the transmission line (302, 304).

Description

TECHNICAL AREA

[0001] The present disclosure relates generally to wireless communication and in particular to tunable broadband distribution circuits. BACKGROUND

[0002] Wireless communication systems are used in a wide variety of telecommunications systems, television, radio and other media systems, data communication networks, and other systems for transmitting information between remote points using wireless transmitters and wireless receivers. A transmitter is an electronic device that propagates an electromagnetic signal, usually by means of an antenna, as in radio, television, or other telecommunications technologies. Transmitters often include signal amplifiers that receive a radio frequency or other signal, amplify the signal by a predetermined gain, and transmit the amplified signal. Conversely, a receiver is an electronic device that receives and processes an electromagnetic wireless signal, usually also by means of an antenna.In certain cases, a transmitter and receiver can be combined into a single device called a transceiver.

[0003] A receiver in a wireless communication device that wishes to transmit and / or receive over a range of frequency bands can use a broadband distribution circuit to send a wireless signal from one part of the wireless communication device to another. Due to the different characteristics of the various frequency bands, the performance of the wireless communication device can change depending on the selected frequency. In particular, due to the frequency-dependent nature of power losses in transmission lines, it can be difficult, if not impossible, to optimize the power transmission of a signal within the distribution circuit for a multiple of frequencies.Therefore, what may be an optimal power transmission configuration for a wireless communication device that wishes to transmit and / or receive over a range of frequency bands may not be optimal for another frequency.

[0004] Known circuit concepts that can be used in transmitters and / or receivers are described, for example, in US 2010 / 0 271 122 A1, DE 10 2007 016 590 A1, DE 10 2009 019 440 A1, US 2006 / 0 030 277 A1 or US 7 583 143 B2. SUMMARY

[0005] It is an object of the present invention to provide an improved tunable broadband distribution circuit for transmitting a wireless signal over a transmission line.

[0006] This task is achieved by a tunable broadband distribution circuit for transmitting a wireless signal over a transmission line according to claim 1, a wireless communication system according to claim 6 and a method according to claim 11.

[0007] A tunable broadband distribution circuit for transmitting a wireless signal over a transmission line is disclosed. The tunable broadband distribution circuit can include a programmable gain buffer, wherein the gain of the programmable gain buffer is based at least partially on a frequency of the wireless signal. The tunable broadband distribution circuit can also include a tuning element configured to modify an effective impedance of the transmission line at least on the basis of the frequency of the wireless signal, wherein the tuning element is electrically coupled to the transmission line.

[0008] The technical advantages of the present disclosure are readily apparent to those skilled in the art from the figures, the description, and the claims contained herein. The objectives and advantages of the embodiments are achieved and realized at least by the elements, features, and combinations that are set forth in particular in the claims.

[0009] It goes without saying that both the preceding general description and the following detailed description are exemplary and explanatory and do not limit the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] For a better understanding of the present disclosure and its features and advantages, reference is now made to the following description in conjunction with the accompanying drawings, wherein: Fig.1 A simplified block diagram of an exemplary wireless signal driver according to certain embodiments of the present disclosure is illustrated; Fig. 2 a simplified circuit diagram of an exemplary wireless signal driver according to certain embodiments of the present disclosure is illustrated; Fig. 3 a detailed circuit diagram of an exemplary tunable broadband distribution circuit according to certain embodiments of the present disclosure is illustrated; Fig. 4 illustrates a detailed circuit diagram of an exemplary tunable broadband distribution circuit according to certain embodiments of the present disclosure; and Fig. Figure 5 illustrates a flowchart of an exemplary method for adjusting the appropriate components of a tunable broadband distribution circuit according to certain embodiments of the present disclosure. DETAILED DESCRIPTION

[0011] Fig.Figure 1 illustrates a simplified block diagram of an exemplary wireless signal driver 100 according to certain embodiments of the present disclosure. For simplicity, the wireless signal driver 100 is represented by a frequency source 102, a buffer driver 104, a transmission line 106, a buffer receiver 108, and a load 110. In some embodiments, the frequency source 102 can be any source of a radio frequency (“RF”) signal to be transmitted as part of a wireless communication system. For example, in some embodiments, the wireless signal driver 100 can be a voltage-controlled oscillator implemented as part of a cellular communication system. In some embodiments, a wireless transmitter can be implemented as an integrated circuit (“IC”) comprising a local oscillator (“LO”).In some configurations, the cellular communication system may require communication over frequencies in the range of 700 to 2,690 MHz. In some embodiments, it may be necessary or desirable to operate flawlessly on some or all of the frequencies within this range. For the exemplary frequency range, a wireless communication system may require an on-chip LO operating in a signal frequency range of 2,800 to 5,380 MHz.

[0012] Furthermore, in some embodiments, the LO signal can be distributed to multiple transmit / receive mixer blocks and / or one or more phase-locked synthesizer blocks. Depending on the configuration of the wireless communication system, these transmit / receive mixer blocks and / or phase-locked synthesizer blocks can be located a considerable distance from the LO source (relative to the IC's dimensions). As the distance increases, the amount of power required to deliver an LO signal of a suitable amplitude increases accordingly. For example, within the previously mentioned frequency range, a distance of more than one nanometer significantly increases the required amount of power.

[0013] Back to Fig.Figure 1 illustrates a detailed diagram of an exemplary embodiment of the exemplary wireless signal driver. For example, the frequency source 102 can supply a 2800 MHz LO signal to the buffer driver 104. In some embodiments, the buffer driver 104 can amplify the signal provided by the frequency source 102 before the signal passes through the transmission line 106 to the buffer receiver 108, as shown below with reference to Fig.2 described in more detail. As previously described in more detail, the transmission line 106 can be any suitable transmission line between the buffer driver 104 and the buffer receiver 108. In some embodiments, the transmission line 106 can be an IC path between the one or more circuits of the buffer driver 104 and the one or more circuits of the buffer receiver 108. The buffer receiver 108 can, in some embodiments, be configured to further process the signal received from the buffer driver 104 via the transmission line 106, as described below with reference to Fig.2 described in more detail. For example, the buffer receiver 108 can amplify the received signal, which may have lower power due to transmission losses incurred while passing through the transmission line 106. After processing, the signal can then proceed to the load 110. As described in more detail above, the load 110 can be any suitable load configured to receive the signal from the frequency source 102. For example, the load 110 can be one or more mixers, multipliers, dividers, multiplexers, receiver block(s), transmission block(s), and / or synthesizer block(s).

[0014] Fig.Figure 2 illustrates a simplified circuit diagram of an exemplary wireless signal driver 100 according to certain embodiments of the present disclosure. In some embodiments, the wireless signal driver 100 may comprise a buffer driver 104, a transmission line 106, and a buffer receiver 108. For the sake of simplicity, the elements 104, 108, and 110 may be represented as those previously described with reference to Fig. 1 correspond to elements 104, 108, 110 described in more detail. For the sake of simplicity, the wireless signal driver 100 is shown receiving an input from a signal source, such as the one previously described with reference to Fig. 1 more precisely described frequency source 102. The wireless signal receiver 100 is also shown to output a signal, such as the one previously described with reference to Fig. 1 more precisely described signal to the load 110.

[0015] Back to Fig.2. In some embodiments, the buffer driver 104 may include transistors 202 and 204. As in Fig. As illustrated in Figure 2, transistors 202 and 204 can be CMOS transistors configured to act as amplifiers of the input signal. After amplifying the signal, the buffer driver 104 can then transmit the signal along the transmission line 106 to the buffer receiver 108. In some embodiments, the buffer receiver 108 can comprise transistors 206 and 208. As shown in Fig. As illustrated in Figure 2, transistors 206 and 208 can be CMOS transistors configured to act as amplifiers of the signal before output.

[0016] As previously mentioned with reference to Fig.As described in more detail in Figure 1, the transmission of the signal over the transmission line 106 can lead to power losses that may impair the overall performance of the wireless communication system. Accordingly, it may be necessary or important to provide a method of signal amplification at multiple points along the transmission path to maximize performance. However, for wireless communication system configurations operating over a wide frequency range, it can be difficult to implement an amplification scheme suitable for the entire frequency range. That is, a segment of the wireless signal driver 100 may exhibit different loss characteristics depending on the frequency of the input signal. This may be at least partially due to the dependence of the impedance value of this segment on the frequency of the input signal.It may be necessary or desirable to change the impedance of different segments of the wireless signal driver 100 in order to optimize the power transmission of the input signal via the wireless signal driver 100.

[0017] Fig. Figure 3 illustrates a detailed circuit diagram of an exemplary tunable broadband distribution circuit 300 according to certain embodiments of the present disclosure. As previously referred to Fig. 1 and Fig.As described in more detail in Section 2, a wireless communication system can include a wireless signal driver, which in some embodiments comprises a buffer driver 104, a transmission line 106, and / or a buffer receiver 108. According to certain embodiments of the present disclosure, the tunable broadband distribution circuit 300 can further comprise one or more switches 312 and a tuning element 306. In some embodiments, the previously described components can be considered to be... Fig. 1 and Fig. The transmission line 106, described in more detail below, can be thought of as being divided into several segments. For example, the transmission line 106 in the exemplary tunable broadband distribution circuit 300 can be divided into several segments. Fig.3. comprise one or more transmission line segments 302, 304. In some embodiments, the transmission line segment 302 can be the section of the transmission line between the buffer driver 104 and the tuning element 306, and the transmission line segment 304 can be the section of the transmission line between the tuning element 306 and the buffer receiver 108. Although two transmission line segments 302, 304 in Fig. As shown in Figure 3, a plurality of transmission line segments can be included in any given implementation without deviating from the scope of protection of the present disclosure. Although likewise only one of each of the buffer driver 104, the tuning element 306 and the buffer receiver 108 in Fig.As shown in Figure 3, a particular implementation of the tunable broadband distribution circuit 300 may require one or more of each element. Therefore, a plurality of elements may be present in each respective implementation without deviating from the scope of protection of this disclosure.

[0018] In some embodiments, the tunable wireless signal driver 300 may include one or more switches 312. The switch 312 can be used to activate specific segments of the buffer driver 104. As previously described with reference to Fig.As described in more detail in section 2, the buffer driver 104 can comprise one or more segments. Each segment can be configured to amplify the frequency source signal by a certain amount. One or more switches 312 can be configured to activate one or more segments of the buffer driver 104, thereby modifying the amount of amplification applied to the frequency source signal. Although a switch in Fig. As illustrated in Figure 3, the tunable broadband distribution circuit 300 may contain one or more switches without deviating from the scope of protection of the present disclosure.

[0019] When the appropriate number of segments of the buffer driver 104 are activated by the appropriate number of switches 312, the input frequency source can be amplified by a necessary or desired amount. This amplified signal can then be passed through the transmission line segment 302 before reaching the tuning element 306. In some embodiments, the tuning element 306 can be a combination of circuit elements configured to change the impedance of the transmission line. As an illustrative example, the tuning element can include a variable capacitor 308 and a variable inductor 310. In other configurations, the tuning element 306 can include only one tunable component or more than two components without deviating from the scope of protection of this disclosure.For example, a tuning element may include an inductor and a variable capacitor, as shown below with reference to . Fig. 4 described in more detail.

[0020] Although furthermore in Fig.Figure 3 shows that the tuning element 306 is located in the middle of the transmission line (dividing the transmission line into transmission line segments 302 and 304). However, the tuning element 306 can be located anywhere along the transmission line without compromising the scope of protection of this disclosure. Depending on the specific design configuration of the tunable broadband distribution circuit 300, the tuning element 306 can be located at either end of the transmission line or at any suitable location along the line. Considerations regarding its placement may include performance characteristics, such as a desired current level, or physical characteristics of the wireless communication system, such as considerations regarding space and / or form factor. Other configurations may require different considerations.

[0021] In some embodiments, the tuning element 306 can act in such a way as to change the effective length of the transmission line. As previously referred to Fig.As described in more detail in Figure 1, in wireless communication systems, different frequencies result in different power levels for a given transmission line length. That is, to optimize power transmission, it may be necessary or desirable to have an optimized transmission line length for a given frequency. However, in wireless communication systems, where a wireless signal driver may be required to transmit and / or receive over a wide range of frequencies, it is not always possible to adjust the physical length of the transmission line for each frequency band. Consequently, some frequencies result in more efficient power transmission than others. In some embodiments, however, the tuning element 306 can be configured to change the magnitude of the impedance along with the transmission line, thereby changing the overall impedance of the transmission line.This can result in a longer or shorter effective transmission line length, as applicable. For example, a higher frequency band may require a shorter effective transmission line length than a lower frequency band. As explained below with reference to... Fig. 4 and Fig. As described in more detail in Section 5, the tuning element 306 can be configured with settings for multiple frequency bands required by a given wireless signal driver. When the wireless communication system wishes to transmit and / or receive on a specific frequency, it can notify the tuning element 306. The tuning element 306 can then adjust the settings of its components to provide the appropriate impedance value associated with the identified frequency. In this way, power transmission can be optimized for a given frequency band.

[0022] Fig.Figure 4 illustrates a detailed circuit diagram of an exemplary tunable broadband distribution circuit 460 according to certain embodiments of the present disclosure. In some embodiments, the wireless signal driver 460 may comprise a plurality of input frequency sources. In the illustrated example, the tunable broadband distribution circuit 460 comprises a frequency source 402, a voltage-controlled oscillator providing an input in the range of 2.6 to 4.1 GHz, and a frequency source 404, a voltage-controlled oscillator providing an input in the range of 3.6 to 5.6 GHz. The frequency sources 402 and 404 are included as examples for better understanding and are not intended to limit the scope of protection of the present disclosure. In some embodiments, the tunable broadband distribution circuit 460 may include switches 406 and 408.Switches 406 and 408 can be electronically and / or mechanically controlled switches configured to pass the signal(s) from frequency sources 402 and 404, respectively. For example, switch 406 can be configured so that, when activated, it allows the signal from frequency source 402 to pass to buffer driver 104. Similarly, switch 408 can be configured so that, when activated, it allows the signal from frequency source 404 to pass to buffer driver 104.

[0023] In some embodiments, the tunable broadband distribution circuit 460 may also include one or more buffer drivers 104. As previously referred to Fig.As described in more detail in sections 1 to 3, the buffer driver(s) 104 can be an amplifier configured to amplify the signal input from frequency sources 402 and 404. The amount of gain applied to the input signal can vary depending on the frequency of the input signal, as previously described in section 1 to 3. Fig. 1 to 3 are described in more detail. After it has been amplified, the signal can then be forwarded to the transmission line.

[0024] In some embodiments - as previously referred to Fig. 3. Described in more detail – the transmission line connected to the tunable broadband distribution circuit 460 can be considered as divided into several transmission line segments if one or more tuning element(s) are introduced in the middle of the transmission line. In the illustrated example of Fig.4. The transmission line is divided into five transmission line segments 410, 414, 416, 418, 422. Depending on the specific configuration, the total length of the transmission line and the arrangement of certain components may be determined by characteristics of the communication system, as previously described with reference to Fig. 3 is described in more detail. In the illustrated example, the total length of the transmission line between the buffer driver 104 and the buffer receiver 108 is 6100 nm. The distance may be longer or shorter for other configurations. Furthermore, the transmission line segments 410, 414, 416, 418, and 422 are shown to have lengths of 1750 nm, 1750 nm, 100 nm, 1250 nm, and 1250 nm, respectively. In other configurations, the number of transmission line segments (if any) may be greater or fewer, and the lengths of these segments may be longer and / or shorter than those illustrated.

[0025] In this example, transmission line segment 410 can be the section of the transmission line between the buffer driver 104 and the tuning element 412. Transmission line segment 414 can be the section of the transmission line between the tuning element 412 and the point where the switch 432 intersects the transmission line. Transmission line segment 416 can be the section of the transmission line between the point where the switch 432 intersects the transmission line and the point where the switch 434 intersects the transmission line. Transmission line segment 418 can be the section of the transmission line between the point where the switch 434 intersects the transmission line and the tuning element 420. Transmission line segment 422 can be the section of the transmission line between the tuning element 420 and the buffer receiver 108.

[0026] In some embodiments, the tunable broadband distribution circuit 460 can comprise a plurality of tuning elements, as previously described with reference to Fig.3 is described in more detail. In the illustrated example, the tunable broadband distribution circuit 460 comprises two tuning elements 412, 420, each including an inductor and a variable capacitor. In some embodiments, a plurality of tuning elements can provide the designer of the wireless communication system with greater flexibility in determining how best to tune the tunable broadband distribution circuit 460. The inductor and the variable capacitor of the tuning elements 412, 420 can be any suitable value necessary to match the impedance of the selected transmission line segment. For example, if the length of the transmission line segments 410, 414 is given, a suitable value for the inductor of tuning element 412 might be 1.62 nH.Given the lengths of the transmission line segments 418 and 422, a suitable value for the adjustable capacitor of the tuning element 420 could be 2.7 nH, as another example. In some embodiments, the adjustable capacitor can be implemented as a plurality of adjustable capacitors. For example, the adjustable capacitor of the tuning element 412 can be implemented as 16 adjustable capacitors with a maximum capacitance of 102 femtofarads (designated as 16 × 10² f). In the same or alternative embodiments, the tuning element 412 can also include an adjustable secondary capacitor. As an illustrative example, this capacitor can have a value of 10 × 10² f. Similarly, a suitable value for the adjustable capacitor of the tuning element 420 can be 12 × 10² f. In the same or alternative embodiments, the tuning element 420 may also include an adjustable secondary capacitor.As an illustrative example, this capacitor can have a value of 7 × 102 f.

[0027] In some embodiments, the tunable broadband distribution circuit 460 may also include switches 432 and 434. Switches 432 and 434 may be configured to allow the output of the appropriate input signal. For example, switch 432 may be configured to allow the output of frequency source 402. Similarly, switch 434 may be configured to allow the output of frequency source 404. One or more output buffers 436 and 438 may be located downstream of switches 432 and 434. In some embodiments, it may be necessary to amplify the signal received at the output buffers 436 and 438. For example, in a wireless communication system that includes cellular communication, it may be necessary or desirable to amplify the output signal to optimize cellular data transmission. The output signal from output buffers 436, 438 can go to wireless network systems 440, 442.As an illustrative example in the case of cellular transmission, the output signal can be configured to transmit data in a protocol compatible with second-generation cellular telecommunications networks (“2G”), third-generation cellular telecommunications networks (“3G”) and / or long-term evolution cellular telecommunications networks (“LTE”).

[0028] In some embodiments, the tunable broadband distribution circuit 460 may also include a synthesizer element 430. In some configurations of the tunable broadband distribution circuit 460, it may be necessary or desirable to include the synthesizer element 439 to maintain desired performance levels of the wireless network system. In some embodiments, the synthesizer element 430 may include a buffer receiver 108, a divider 426, and a prescaler 428.

[0029] During operation, the developer of the tunable broadband distribution circuit 460 can determine which frequency bands are important for optimizing the circuit. For example, it may be necessary or desirable to optimize the circuit in the 3 GHz, 4 GHz, and 5 GHz bands. At each of these frequencies, the impedance of the transmission line within the circuit can vary. Consequently, power transmission may not be optimal. By modeling the behavior of the circuit, settings for the tuning elements 412 and 420 can be determined. For example, the tuning elements 412 and 420 may have possible settings of 0, 5, 10, and 15. In this example, the settings correspond to the values ​​that represent four binary numbers: 0000, 0101, 1010 and 1111 respectively.In this example, the binary numbers represent whether each of the four previously described adjustable capacitors is enabled. For example, a setting of zero (0000) would mean that all four adjustable capacitors are disabled. Similarly, a setting of 15 (1111) would mean that all four adjustable capacitors are enabled. Although these four settings are illustrated, more, fewer, or other settings can be implemented in a given configuration without infringing upon the scope of protection of this disclosure.

[0030] As a result of the modeling, it can be determined that setting 0 is best suited for the 3 GHz frequency band, setting 5 is best suited for the 4 GHz frequency band, setting 10 provides good performance for the 4 GHz frequency band, and setting 15 is best suited for the 5 GHz band.

[0031] TABLE 1 below illustrates some exemplary modeling values ​​for the transmission line impedance in the different frequency bands using the different values ​​for the tuning elements 412, 420. TABLE 1 Tuning element settings Real impedance - 3 GHz Imaginary impedance - 3 GHz Real impedance - 4 GHz Imaginary impedance - 4 GHz Real impedance - 5 GHz Imaginary impedance - 5 GHz 0 94,9708 154,591 26,6933 -3,7228 68,2366 40,4176 5 24,7851 89,5711 143,114 -128,583 29,4246 13,2042 10 20,2406 79,3098 310,212 168,259 31,9059 -16,0296 15 14,6138 62,7448 25,0461 106,733 127,135 238,232

[0032] After modeling the performance of the tunable distribution circuit 460, the wireless communication system can implement systems or methods for configuring the buffer driver 104 and / or the tuning elements 412, 420 with the appropriate settings for the desired frequency band. For example, in a cellular communication headset, a processor can identify that the headset is within range of a 3G network and therefore must transmit on a frequency suitable for the network. The processor can then determine which settings are required for the desired frequency band and notify the buffer driver 104 and / or the tuning elements 412, 420 of the appropriate settings. In some embodiments, this operation can be performed using a lookup table stored in the processor's firmware.

[0033] In this way, the buffer driver 104 and / or the tuning elements 412, 420 can be adjusted to the appropriate settings to optimize power transmission for a specific frequency band. This capability can also be applied to any number of frequency bands suitable for the tunable broadband distribution circuit 460. The tunable broadband distribution circuit 460 can therefore accommodate multiple frequency bands within the same LO circuit.

[0034] Fig.Figure 5 illustrates a flowchart of an exemplary method 500 for adjusting the appropriate components of a tunable broadband distribution circuit 460 according to certain embodiments of the present disclosure. In some embodiments, the method 500 may include steps 502 to 512. Although illustrated as separate steps, various steps may be subdivided into additional steps, combined into fewer steps, or omitted, depending on the desired implementation.

[0035] In some embodiments, the method may begin at step 502, in which the appropriate settings for a programmable gain buffer are determined. As previously referred to Fig.As described in more detail in sections 1 to 4, the programmable gain buffer can be the buffer driver 104. After determining the settings for the programmable gain buffer, procedure 500 can proceed to step 504. In step 504, procedure 500 can determine the settings for a first tuning element. As previously described with reference to Fig. As described in more detail in Section 4, a first tuning element can be the tuning element 412. Suitable modeling of the behavior of the tunable wireless signal driver 460 can lead to a series of settings for the tuning element 412, corresponding to a plurality of frequency bands in which operation is desired. After determining the settings for a first tuning element, procedure 500 can proceed to step 506.

[0036] At step 506, procedure 500 can determine whether any further tuning elements are present. If so, the procedure can return to step 504. If not, the procedure can proceed to step 508. At step 508, the procedure can determine whether there has been an indication of a frequency band request. As previously referred to Fig.As described in more detail in section 5, the programmable gain buffer and / or tuning elements can receive an indication of the appropriate settings, based at least partially on the desired frequency band. If no indication is received, procedure 500 can proceed to step 510. At step 510, the procedure can wait a predetermined amount of time before checking for a frequency indicator again. For example, in a particular configuration, it may be necessary or desirable to check frequently, i.e., every second. In other configurations, it may only be necessary or desirable to check periodically, i.e., every 30 seconds. After waiting, procedure 500 can return to step 508.

[0037] If a frequency indicator has been received, Procedure 500 can proceed to step 512. In step 512, Procedure 500 can adjust the programmable gain buffer and / or tuning elements to the appropriate settings. After the elements have been appropriately adjusted, Procedure 500 can return to step 508 in preparation for the possibility of a change in frequency requirements.

[0038] It is apparent to a person skilled in the art that, for this and other processes and procedures disclosed herein, the functions performed in the processes and procedures can be implemented in different sequences. Furthermore, the steps and operations presented are provided only as examples, and some of the steps and operations may be optional, combined into fewer steps and operations, or extended to include additional steps and operations without diminishing the essential nature of the disclosed embodiments. As an illustrative example, Method 500 may also include determining whether there are additional programmable gain buffers that require adjustment.It goes without saying that, although the present disclosure has been described in detail, various changes, replacements and modifications may be made to it without deviating from the inventive concept and scope of protection of the present disclosure as defined by the attached claims.

[0039] All examples and conditional expressions mentioned herein serve educational purposes to facilitate the reader's understanding of the invention and the concepts that the inventor contributes to the advancement of technology, and are therefore to be interpreted as not being limited to these specifically mentioned examples and conditions. It is understood that, although embodiments of the present invention have been described in detail, various modifications, substitutions, and alterations may be made to them without departing from the concept and scope of protection of the present invention.

Claims

Tunable broadband distribution circuit (300, 460) for transmitting a signal in a selected frequency band chosen from a plurality of frequency bands over a transmission line (302, 304) of a physical length, wherein the tunable broadband distribution circuit (300, 460) comprises: a plurality of switches (406, 408) configured to select from a plurality of local oscillators (402, 404) to select frequency band 10, wherein the plurality of local oscillators (402, 404) are configured to provide signals in the plurality of frequency bands; a gain buffer (104) configured to amplify the signal and output the amplified signal to the transmission line, wherein a gain of the gain buffer (104) can be specified at least based on the selected frequency band of the signal;and a tuning element (306) configured to modify an effective length of the transmission line (302, 304) by varying an amount of the impedance in series with the transmission line at least on the basis of the selected frequency band of the signal, wherein the tuning element (306) is electrically coupled to the transmission line (302, 304). Tunable broadband distribution circuit (300, 460) according to claim 1, wherein the majority of frequency bands are in the high-frequency range. Tunable broadband distribution circuit (300, 460) according to one of the preceding claims, wherein the tuning element (306) comprises a controllable capacitor (308). Tunable broadband distribution circuit (300, 460) according to one of the preceding claims, wherein the tuning element (306) comprises a controllable inductor (310). Tunable broadband distribution circuit (300, 460) according to one of the preceding claims, wherein an effective impedance of the transmission line (302, 304) comprises a non-zero reactance. Wireless communication system comprising: a baseband processor configured to operate in a plurality of frequency bands; an antenna; a tunable broadband distribution circuit (300, 460) for transmitting a signal in a selected frequency band chosen from the plurality of frequency bands over a transmission line (302, 304) having a physical length within the tunable broadband distribution circuit (300, 460), wherein the tunable broadband distribution circuit (300, 460) comprises: a plurality of switches (406, 408) configured to select from among a plurality of local oscillators (402, 404) to select the frequency band, wherein the plurality of local oscillators (402, 404) are configured to provide signals in the plurality of frequency bands;a gain buffer (104) configured to amplify the signal and output the amplified signal to the transmission line, wherein the gain of the gain buffer can be specified at least on the basis of the selected frequency band of the signal; and a tuning element (306) configured to modify an effective length of the transmission line (302, 304) by varying an amount of the impedance in series with the transmission line at least on the basis of the selected frequency band of the signal, wherein the tuning element (306) is electrically coupled to the transmission line (302, 304). Wireless communication system according to claim 6, wherein the majority of frequency bands are in the high-frequency range. Wireless communication system according to one of claims 6 to 7, wherein the tuning element (306) comprises an adjustable capacitor (308). Wireless communication system according to one of claims 6 to 8, wherein the tuning element (306) comprises an adjustable inductor (310). Wireless communication system according to one of claims 6 to 9, wherein an effective impedance of the transmission line (302, 304) comprises a non-zero reactance. Method (500) for optimizing the power transmission of a signal in a selected frequency band chosen from a plurality of frequency bands over a transmission line (302, 304) of a physical length within a tunable broadband distribution circuit, (300, 460) wherein the method comprises: Determining (502) a plurality of settings for a gain buffer (104), wherein the plurality of settings are at least partially based on a desired frequency band, the desired frequency band being selected from the plurality of frequency bands; Determining (504) a plurality of settings for a tuning element electrically coupled to the transmission line (302, 304), wherein the plurality of settings are at least partially based on a desired frequency band, the desired frequency band being selected from the plurality of frequency bands; Receiving (508) an indication of the desired frequency band;Setting (512) the gain of the gain buffer according to the plurality of settings for the gain buffer and the indication of the desired frequency band; and setting the tuning element according to the plurality of settings for the tuning element and the indication of the desired frequency band, in order to enable the tuning element to change an amount of the impedance in series with the transmission line, thereby setting an effective length of the transmission line (302, 304). The method according to claim 11, further comprising checking whether the desired frequency band has changed. Method according to claim 11 or 12, wherein the majority of frequency bands are in the high-frequency range. Method according to one of claims 11 to 13, wherein the tuning element is configured to modify an effective impedance of a transmission line of the tunable wireless receiver at least on the basis of the frequency of the wireless signal, wherein the tuning element is electrically coupled to the transmission line. Method according to claim 14, wherein an effective impedance of the transmission line comprises a non-zero reactance.

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