NL2005607C2

NL2005607C2 - A configurable communication device.

Info

Publication number: NL2005607C2
Application number: NL2005607A
Authority: NL
Inventors: Johan Wilhelm Frederik Laak
Original assignee: Jtl Engineering B V
Priority date: 2010-11-01
Filing date: 2010-11-01
Publication date: 2012-05-02

Description

TITLE

A configurable communication device.

TECHNICAL FIELD

5 The present invention relates to radio telecommunications and, in particular, to a communication device comprising an integrated circuit arranged for performing radio frequency functionality.

BACKGROUND

10 Communication devices, such as mobile telephones, network computers, Personal Digital Assistants, PDAs, wired and wireless modems, etc., often comprise an Integrated Circuit, IC, for performing most of the Radio Frequency, RF, functionality. External to the IC, these communication devices generally comprise a line or antenna matching circuit for matching RF signals exchanged between a line or cable or 15 antenna and RF circuitry.

RF signals to or from a line or an antenna are exchanged over an RF input/output port of the IC. Generally, a Low Noise Amplifier, LNA, is integrated on the IC and connects to the input part of the input/output port, for amplifying RF signals received 20 from a line or antenna. Parallel to the LNA, a Power Amplifier, PA, may connect to the output part of the input/output port, to amplify RF signals to be transmitted over the line or antenna.

The RF input/output port may be configured as a balanced or an 25 unbalanced port. If, for example, balanced RF signals are exchanged over the RF input/output port, these signals need to be transformed to unbalanced RF signals to feed a rod antenna, for example. A similar transformation is required for RF signals received from such an antenna. In such a case, the antenna matching circuit generally comprises a balun to transform balanced signals at the RF input/output port of the RF circuitry to 30 unbalanced signals at the antenna.

If, for example, a balun is used for transforming balanced signals to, and from, unbalanced signals, in connection with a rod antenna or in general a monopole antenna, the impedance of the antenna needs to be matched to the impedance seen at 2 the balanced side of the balun. To this end, the antenna matching circuit comprises electrical components to adjust the impedance transformation performed by the balun.

Due to changes in the environment, such as temperature, metal objects 5 or the human body in the neighborhood of an antenna, PA and LNA settings, spreading and tolerances of component values, aging, and the like, for optimal performance of the RF circuitry, it would be desirable to have the impedance matching to be adjustable.

If the communication device is arranged for both RF receiving 10 functionality as well as transmitting functionality, and if in both cases a balanced to unbalanced, and vica versa, transformation is required, the antenna matching circuit may comprise two baluns, a receiving balun and a transmitting balun. The receiving balun having RF transformation properties specifically adapted for receiving RF signals and the transmitting balun having RF transformation properties specifically adapted for 15 transmitting RF signals.

In such a case, the antenna matching circuit generally comprises an RF Rx/Tx diversity switch to connect the antenna to either the transmitting balun or the receiving balun, for transmitting RF signals or receiving RF signals, respectively.

20

Further, a communication device may comprises multiple antenna’s or multiple lines, for example, one antenna or line for receiving and an other antenna or line for transmitting an RF signal or even three antenna’s each adapted for use at a specific one of the three different frequencies, for example. Such as with a communication device 25 for use at three different frequencies, or frequency bands, for example a wireless telephone operating in the 900MHz, 1800MHz and 1900MHz communications band.

In such a case, the antenna matching circuit generally comprises at least one RF antenna diversity switch to connect either one of the antennas to the RF 30 circuitry on the IC.

If the communication device comprises at least two baluns, as described above, and multiple antennas, the antenna matching circuit thus comprises both Rx/Tx and antenna diversity switches.

3 RF switches are known to occupy a relatively large amount of space, i.e. board space on a Printed Circuit Board, PCB, relatively high power consumption and switches often require additional electrical components, such as capacitors and inductors, to function properly. These RF switches are also relatively costly.

5

Besides or in addition to the RF circuitry such as an LNA, PA and modulation and demodulation circuits, the 1C may also comprise configurable switching networks. Semiconductor elements like bipolar transistors and field effect transistors, operating as switches, pin diodes and varactors are examples of configurable elements 10 which, together with other electrical elements like capacitors and resistors, for example, form configurable switching networks integrated on the IC. The electrical configuration and properties of the network can be configured by setting the configurable elements in a particular state.

15 SUMMARY

It is an object of the present invention to provide an improved communication device arranged for supporting RF line or antenna matching, antenna diversity and Rx/Tx diversity, to meet present and future demands of designers and users of such a communication device.

20

In a first aspect there is provided a communication device, comprising an Integrated Circuit, IC, having a configurable switching network comprising a configurable switching network port; Radio Frequency, RF, signal processing circuitry having an RF signal processing circuitry port for transferring RF signals; a coupling circuit 25 having a coupling circuit processing circuitry port connected to the RF signal processing circuitry port, and a coupling circuit line port for communicating RF signals, the coupling circuit being arranged for coupling RF signals between the coupling circuit processing circuitry port and the coupling circuit line port. The communication device further comprises a line signal circuit, the line signal circuit having a line signal circuit line port 30 connected to the coupling circuit line port, and a line signal circuit network port connected to the configurable switching network port, wherein the line signal circuit is arranged for controlling, by the configurable switching network, the coupling of RF signals between the coupling circuit processing circuitry port and the coupling circuit line port.

4

With the communication device disclosed above, using a general RF circuit configuration comprised by a coupling circuit and a line signal circuit connected as disclosed for connecting a line or antenna to the RF signal processing circuitry, RF line or antenna matching, antenna diversity and Rx/Tx diversity can be supported and controlled 5 by a configurable network on the 1C. That is, with this configuration it is possible to provide for an RF communication architecture wherein a configurable switching network integrated in the 1C controls the coupling of RF signals to and from a coupling circuit line port for connecting communication line(s) or antenna(s), as well as impedance matching of a line or antenna. Accordingly, with the invention, using a configurable switching 10 network on an IC, the number of separate external RF switches can be reduced or even completely omitted.

By using less switching components external to the IC, the robustness of the communication device increases. External components, such as switches, increase 15 the complexity of external circuits, and therefore exposing a risk not to fit with specifications of the communication device. Furthermore, the invention provides an improvement in efficiency and an improvement in the ability to configure or tune the communication device.

20 Using the invention, RF signals are processed by the RF signal processing circuitry which are communicated to the outside world using the coupling circuit line port to which, for example, an antenna is connected. Usually, these RF signals comprise a carrier wave at an operating frequency of the communication device above 100 MHz. The communication device according the invention may be arranged for 25 operating at different operating frequencies.

In an aspect according to the invention the RF signal processing circuitry operates as an RF receiver circuit and/or as an RF transmitter circuit.

Although the RF signal processing circuitry may be arranged separate 30 from the IC comprising the configurable switching network, in another aspect of the invention, the RF signal processing circuitry and the configurable network are integrated on the same IC, of which the configurable switching network port and the RF signal processing circuitry port are electrically functionally separated.

5

The configurable switching network, in its most simple embodiment, comprises a switch or any other type of electrically controllable active components. In yet another aspect of the invention, the line signal circuit and the coupling circuit comprise only electrically passive components. By using only passive components in the circuits 5 external to the 1C a significant improvement in energy efficiency and robustness of the communication device is achieved. Active components may be integrated in the configurable switching network which, however, is more energy efficient compared to active components external to the 1C.

10 The circuits external to the IC, that is the coupling circuit and the line signal circuit, in a further embodiment of the invention may only comprises components having functionally time-invariant small signal parameters. In such a case, flaws attributed to, for example, component spread or component degradation are corrected for. Note that the term “small signal parameters” refers to a linear behavior of such parameters in an 15 operating range of the communication device.

According to the invention, the configurable network may comprise a variety of components, for example a grounding switch, a filter circuit, a configurable capacitor, a series resonance network, a parallel resonance network, etc. In one example, 20 the coupling circuit and the line signal circuit comprise, jointly, a transformer and the configurable switching network comprises a grounding switch, wherein the transformer is configured as a balun when the switch is conductive.

Generally, according to the invention, the operating frequency of the 25 communication device is above 100 MHz. The communication device may be applicable for different frequency bands, like the Global System for Mobile communications, GSM, frequency band, the Industrial, Scientific and Medical, ISM, frequency bands, the Ultra High Frequency, UHF, band, etc.

30 In a further aspect of the invention, the line signal circuit is a impedance transformation circuit, for example a circuit comprising a transmission line. The line circuit is arranged for creating a functionally significant phase difference between a signal at the configurable switching network port and the signal at the line signal circuit line port, for example by using a transmission line. The impedance circuit may also comprise a 6 capacitor, inductor, or any other type of component, for example for adjusting the impedance transformation.

If, for example, this impedance transformation circuit is connected to an 5 antenna, the impedance seen from the antenna can be configured using the configurable switching network and the line signal circuit. Here, the antenna is connected to the line signal circuit line port.

With a impedance transformation circuit connected to an antenna, it 10 becomes possible to tune the antenna by controlling the configurable switching network integrated on the IC. This makes the configurable switching network together with the line signal circuit, comprising a transmission line, a flexible solution to tune out unexpected design behavior.

15 If, for example, a certain point in the line signal circuit or the coupling circuit is too inductive, the configurable network can correct for this inductiveness by, for example, switching a capacitive impedance, such as a capacitor or an element providing capacitive properties, in parallel.

20 If the line signal circuit comprises a transmission line, the length of that transmission line is, in an example of the present invention, approximately a quarter of a wave length of the operating frequency, such that it provides an impedance inversion.

In a further aspect of the invention, the coupling circuit comprises a 25 impedance transformation circuit, for example a circuit comprising transmission lines. Here, the line signal circuit is arranged for creating functionally significant different impedance’s at the coupling circuit line port, as function of the setting of the configurable switching network. Using this architecture, the impedance seen from the coupling circuit line port depends on the setting of the configurable switching network.

30

The line signal circuit may comprise a transmission line which transforms the impedance at the configurable switching network port to an open or a short at an operating frequency of the device. If the impedance is considered to be an open, the line signal circuit does not influence signaling in the coupling circuit. If the impedance is 7 considered to be a short, the power from the coupling circuit is reflected at the line signal circuit line port. Using this architecture, a switch, external to the 1C, arranged for switching between an open and a short, becomes superfluous. As impedance transformation circuits are frequency depended, this architecture is especially suitable for applications in 5 which RF power is mainly bundled in a small frequency band.

For example, the coupling circuit is a transmission line of a quarter-wave length at the frequency of operation. The coupling circuit processing circuitry port is connected the transmission line and the coupling circuit line port is connected to the 10 transmission line and an antenna. The line signal circuit also comprises a transmission line with the line signal circuit line port connected to one end of the transmission line and the line signal circuit network port connected to the other side of the transmission line. The impedance at the line signal circuit line port may be controlled by the configurable network, by, for example, using a signal grounding switch. The switch is arranged for 15 controlling the impedance be considered as a short or an open referred to ground.

If it is considered as a short, the antenna is shunted by a short and the impedance of the coupling circuit processing circuitry port is an open due to the impedance inversion of the quarter-wave length transmission line. If is it considered as an 20 open, the coupling circuit processing circuitry port is functionally connected to the antenna. The configurable switching network is therefore arranged to functionally switch in or switch out an antenna from the coupling circuit processing circuitry port.

The above mentioned example utilizes an antenna but any other type of 25 communication medium may be used, like, for example, a communication line or cable or a port to another part of the communication device.

In another aspect of the invention the configurable switching network may have multiple states, such that the line signal circuit line port is arranged for creating 30 multiple reflections for RF signals and thereby providing a method to tune the impedance at the coupling circuit line port.

Using the architectures explained above a communication device may be arranged for Rx/Tx diversity as well as antenna diversity, while switches are placed on 8 the IC.

In yet another aspect of the invention, the communication device further comprises further RF signal processing circuitry having a further RF signal processing 5 circuitry port; a further configurable switching network having a further configurable switching network port; a further coupling circuit having a further coupling circuit line port and a further coupling circuit processing circuitry port; and a further line signal circuit having a further line signal circuit line port and a further line signal circuit network port, wherein the further coupling circuit processing circuitry port is connected to the further RF 10 signal processing circuitry port, the further line signal circuit network port is connected to the further configurable switching network port, and the further coupling circuit line port is connected to the further line signal circuit line port.

This aspect of the invention, in an embodiment wherein the coupling 15 circuit line port is connected to the further coupling circuit line port, allows for an architecture that supports the use of Rx/Tx diversity, for example wherein the RF signal processing circuitry and further RF signal processing circuitry are arranged for receiving and transmitting RF signals, respectively.

20 In such an embodiment, the further coupling circuit and the further line signal circuit, jointly, may comprise a further RF transformer circuit having a further primary transformer port and a further secondary transformer port, wherein the further primary port is coupled to the further coupling circuit processing circuitry port, the further secondary transformer port having a further first terminal and a further second terminal, 25 wherein the further first terminal is coupled to the further line signal circuit line port and the further second terminal is coupled to the further line signal circuit network port.

The coupling between the primary and secondary transformer ports of the RF transformer circuit and the ports, respectively, may comprise a capacitor, inductor, 30 or any other type of component, for example for blocking undesired RF signals.

In another embodiment, the communication device comprises further RF signal processing circuitry having a further RF signal processing circuitry port; a further configurable switching network having a further configurable switching network port; a 9 further coupling circuit having a further coupling circuit line port and a further coupling circuit processing circuitry port; and a further line signal circuit having a further line signal circuit line port and a further line signal circuit network port, wherein the further coupling circuit processing circuitry port is connected to the further RF signal processing circuitry 5 port, the further coupling circuit line port is connected to the further line signal circuit line port, the further line signal circuit network port is connected to the further configurable switching network port, and wherein the RF signal processing circuitry and the further RF signal processing circuitry form a single RF signal processing circuitry having a single RF signal processing circuitry port forming the RF signal processing circuitry port and the 10 further RF signal processing circuitry port.

For example, if two line signal circuits comprise a transmission line, such that the configurable switching network is arranged to control the impedance seen into the end of the transmission line, then one antenna may be shunted with a short to ground and 15 a second antenna with an open. A shunt connection with an open does not influence the antenna, but a shunt connection with a short causes all power to be reflected. If these two antennas are each connected via a transmission line of a quarter-wave length to a single RF signal processing circuitry port, the antenna which is shorted is considered as an open and the antenna shunted with the open is connected to the line port. Using this 20 architecture an external switch for switching between these two antennas is superfluous. In other words, this architecture provides for antenna diversity while the antenna switch is integrated in the IC.

Furthermore, if the configurable switching networks are set such that the 25 impedance seen into a transmission line from the antenna is not a short but any other impedance, not being significant dissipative, for example an impedance with a high Q value, then this impedance is parallel to the antenna impedance, thereby tuning the antenna impedance to a different value. This allows both antennas to be used at the same time. Therefore, if the configurable switching networks are arranged to provide either a 30 short, open or any other high Q impedance, the control of the antenna is not merely the selection of one of them, but also a method to tune them and/or use both antennas at the same time. The contribution of each of the antennas to the total amount of power transferred to/from the single RF signal processing circuitry port is controlled by the high Q impedances presented to the antenna.

10

In this example, the line signal circuits as well as the coupling circuits comprise impedance transforming circuits, for example implemented using transmission lines.

5 In another aspect, the communication device further comprises a third and fourth configurable switching network having a third and fourth configurable switching network port, respectively, a third and fourth coupling circuit having a third and fourth coupling circuit line port and a third and fourth coupling circuit processing circuitry port, respectively, and a third and fourth line signal circuit having a third and fourth line signal 10 circuit line port and a third and fourth line signal circuit network port, respectively, wherein the third line signal circuit network port is connected to the third configurable switching network port, the third coupling circuit line port is connected to the third line signal circuit line port, the fourth line signal circuit network port is connected to the fourth configurable switching network port, the fourth coupling circuit line port is connected to the fourth line 15 signal circuit line port, the third coupling circuit processing circuitry port is connected to the fourth coupling circuit processing circuitry port forming a common coupling circuit processing circuitry port, and wherein the common coupling circuit processing circuitry port is connected to the coupling circuit line port and the further coupling circuit line port.

20 This embodiment allows for both Tx/Rx and antenna diversity.

In yet another aspect, the invention provides for a communication device, such as a mobile telephone, network computer, Personal Digital Assistant, PDA, or any other type of wired or wireless communication device comprising user interface 25 equipment.

The above-mentioned and other features and advantages of the invention will be best understood from the following description referring to the attached drawings. In the drawings, like reference numerals denote identical parts or parts 30 performing an identical or comparable function or operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 schematically discloses a part of a communication device comprising an IC, RF signal processing circuitry, line signal circuit and a coupling circuit 11 according to an example of the invention.

Figure 2 schematically discloses a part of a communication device comprising an IC and multiple line signal circuits, RF signal processing circuitry and 5 coupling circuits according to an example of the invention.

Figure 3 schematically discloses a part of a communication device comprising an IC, line signal circuit and a coupling circuit, wherein the coupling circuit and line signal circuit, jointly, comprises a transformer, according to an example of the 10 invention.

Figure 4 schematically discloses a part of a communication device comprising an IC, and multiple line signal circuits and coupling circuits, wherein a coupling circuit and line signal circuit, jointly, comprise a transformer, according to an example of 15 the invention.

Figure 5 schematically discloses a part of a communication device comprising an IC, and multiple line signal circuits and coupling circuits, wherein the coupling circuits comprise a transmission line, according to an example of the invention.

20

Figure 6 schematically discloses a part of a communication device comprising an IC, multiple line signal circuits and coupling circuits, wherein the coupling circuits and line signal circuit comprise transformers and transmission lines, according to an example of the invention.

25

DETAILED DESCRIPTION

Figure 1 discloses a part of a communication device comprising an IC, RF signal processing circuitry, line signal circuit and a coupling circuit according to an example of the invention.

30

Here, a part of the communication device 101 is shown, which processes RF signal communications. The part of the communication device 101 comprises a transceiver Integrated Circuit, IC, 102 having a configurable switching network 112 with a configurable switching network port 113. As an example, a transceiver 12 IC 102 is illustrated, however it is also possible to use solely a receiver IC or a transmitter IC in accordance with the present invention. The IC 102, further, does not need to solely process RF signals. Often the IC 102 is also arranged to perform several other types of data processing simultaneously, if the IC 102 possesses capabilities to do so.

5

The part of the communication device 101 further comprises RF signal processing circuitry 103, having a RF signal processing circuitry port 104, wherein the RF signal processing circuitry 103 is arranged for handling RF signals. The RF signal processing circuitry 103, for example, is arranged to process received RF signals, and/or 10 to generate RF signals to be transmitted. The RF signal processing circuitry 103 is placed external to the IC 102, however, in other aspects of the invention, the RF signal processing circuitry 103 is integrated in the IC 102. In an aspect of the invention, the RF signal processing circuitry port 104 and the configurable switching network port 113 are functionally, electrically separated.

15

The part of the communication device 101 further comprises a coupling circuit 105, having a coupling circuit processing circuitry port 106 connected to the RF signal processing circuitry port 104, and a coupling circuit line port 107. The coupling circuit 105 is arranged to couple RF signals between the coupling circuit processing 20 circuitry port 106 and the coupling circuit line port 107. If the part of the communication device 101 is a wireless communication device, the coupling circuit line port 107 is connected to an antenna (not shown), possibly via an additional circuit. In case of a wired communication device, a wire/cable is connected to the coupling circuit line port, i.e. a network cable or an optical fiber, possibly via an additional circuit.

25

Further, the part of the communication device comprises a line signal circuit 109, arranged to, jointly with the configurable switching network 112, control the coupling circuit 105, for example to control the coupling between the coupling circuit processing circuitry port 106 and the coupling circuit line port 107. The line signal circuit 30 109 is connected to the coupling circuit line port 107 via the line signal circuit line port 111, and is connected to the configurable switching network port 113 via the line signal circuit network port 110.

An advantage of the part of the communication device 101 described 13 above, is that the configurable switching network 112 is integrated in the IC 102, so that no external configurable components, for example switches or pin diodes, are necessary to control the coupling of the coupling circuit 105. Since the configurable switching network is integrated in the IC 102, it is also possible to continuously adjust control 5 settings for the coupling circuit 105, using firmware or any type of software.

The part of the communication device 101 may further comprise user interface equipment 115 to interface with a user.

10 Figure 2 discloses a part of a communication device comprising an IC

and multiple line signal circuits, RF signal processing circuitries and coupling circuits according to an example of the invention.

Here, the part of the communication device 201 comprises an IC 202 15 having two configurable switching networks 203, 220, each having a configurable switching network port 204, 221, and two integrated RF signal processing circuitries 224, 222, each having an RF signal processing circuitry port 225, 223. Both RF signal processing circuitries 224, 222 are integrated in the IC 202. However, according to the invention, the RF signal processing circuitries 224, 222 may also be placed external to the 20 IC 202. RF signal processing circuitry 1, 224, may be arranged as solely a receiving circuit and RF signal processing circuitry 2, 222, may be arranged as solely a transmitting circuit.

The part of the communication device 201 further comprises two 25 coupling circuits 208, 213, each having a coupling circuit processing circuitry port 209, 214. The coupling circuits 208, 213 are arranged to couple signals between the coupling circuit processing circuitry port 209, 214 and the coupling circuit line ports 211, 216.

The part of the communication device 201 further comprises two line 30 signal circuits 205, 217 each having a line signal circuit line port 207, 219 connected to the coupling circuit line port 211, 216 respectively, and a line signal circuit network port 206, 218 connected to the configurable switching network ports 204, 221, respectively.

The coupling circuit line ports 211, 216 are connected to each other to 14 form one common RF line port 212.

By controlling the configurable switching networks 203, 220, the part of the communication device 201 is configured to transform signals between either RF signal 5 processing circuitry 1 or RF signal processing circuitry 2 to the common RF

communication port 212.

The advantage of the architecture shown in figure 2, is that switches external to the IC, arranged for switching between transmitting mode and receiving mode, 10 become superfluous. These switches are integrated in the configurable switching networks 203, 220 which are arranged to, jointly with the line signal circuits 205, 217, control the coupling of the coupling circuits 208, 213.

Figure 3 discloses a part of a communication device comprising an IC, a 15 line signal circuit and a coupling circuit, wherein the coupling circuit and line signal circuit, jointly, comprises a transformer, according to an example of the invention.

Here, the part of the communication device 301 comprises an IC 302, comprising a configurable switching network 304 having a configurable switching network 20 port 305, and RF signal processing circuitry 314, having an RF signal processing circuitry port 303. The coupling circuit 306 and the line signal circuit 310 combined comprise a transformer 313, which electromagnetically couples signals between the coupling circuit 306 and the line signal circuit 310 referred to with the dashed dotted line referenced 315.

25 Here, RF signals are coupled to, and from, the coupling circuit line port

308 and the coupling circuit processing circuitry port 307 via the transformer 313. A

secondary side of the transformer 313 is connected via the line signal circuit network port 311 to the configurable switching network port 305.

30 The configurable switching network 304 may comprise a switch that provides an open or a short to ground. Here, using this aspect of the invention, the switch in the configurable switching network 304 determines the impedance seen in the RF communication port 308. If the switch is closed, the transformer 313 acts as a balun, and the coupling circuit line port 308 provides the unbalanced output, or input, of the balun. If 15 the switch is open the secondary winding of the transformer 313, seen from the IC 302, is floating and the impedance of the coupling circuit line port 308 is open or at least reflective.

5 In this example of the present invention a configurable balun with a switch integrated in the IC 302 for use in communication systems, such as a wireless transceiver, is depicted. By controlling the secondary side of the transformer 313 using a configurable switching network 304, a switch external to the integrated circuit 302 is omitted and the impedance transformation the transformer 313 performs is controlled. 10 Using this architecture, among others, a performance increase and a robustness increase is achieved.

According to the invention, the configurable switching network 304 can further comprise a switch to ground which may be opened or closed, or a switch to ground 15 with a series capacitor, so DC is always blocked, or a switch to ground with a variable series capacitor, or a number or parallel switches with or without a series capacitor such that the impedance over the network is either open, short or a programmable capacitor, or a switch to ground with a series resonant circuit in series, or a switch to ground with a series resonant circuit with at least one programmable capacitor in series, or a switch to 20 ground in a parallel resonant circuit, or a switch to ground in a parallel resonant circuit and the frequency at which the circuit is in resonance can be changed, or a combination of these above mentioned configurations connected in parallel.

Using the configurable switching network 304 integrated in the 25 integrated circuit 302, the impedance to ground that is connected to the secondary winding of the transformer 313 may be controlled in time by changing the state of the switch or switches. If it forms a short circuit, the transformer 313 performs the balanced to unbalanced RF signal coupling. If it forms an open circuit, the transformer 313 isolates the balanced port from the unbalanced port.

30

If it forms a short at a certain operating frequency due to, for example, a series resonance circuit, an RF signal at that frequency is converted from/to balanced to/from unbalanced. If the configurable switching network 304 forms an open at a certain operating frequency due to, for example, a parallel resonant circuit, it isolates the 16 balanced port from the unbalanced port at that operating frequency.

According to the invention, the transformer 313 may also be provided in a PCB, where primary and secondary windings are construed using a conductive layer.

5 For example, the primary and secondary windings are both provided in the top layer of a PCB, or at least partly provided in different layers of the PCB.

Figure 4 discloses a part of a communication device comprising an IC, and multiple line signal circuits and coupling circuits, wherein a coupling circuit and line 10 signal circuit, jointly, comprise a transformer, according to an example of the invention.

Here, the part of the communication device 401 comprises an IC 402, having two configurable switching networks 403, 420, each having a configurable switching network port 404, 421, and two RF signal processing circuitries, 422, 424, each 15 having an RF signal processing circuitry port 423, 425. The part of the communication device 401 further comprises two coupling circuits 405, 406, having two coupling circuit processing circuitry ports 409, 414 connected to the RF signal processing circuitry ports 423, 425, and two line signal circuits 407, 417, which, jointly, comprise two transformers 426, 427.

20

The line signal circuit line ports 413, 419 are connected to the coupling circuit line ports 411,416 and the line signal circuit network ports 415, 418 are connected to the configurable switching network ports 404, 421. The coupling circuit line ports 411, 416 are connected to form one common RF line port 412 to the outside world.

25

The advantage of the above mentioned architecture for the part of the communication device 401, is that external and also different transformers 426, 427 may be used for sending and receiving RF signals. The configurable switching networks 403, 420 are arranged to control the coupling of the coupling circuits 405, 406, i.e. the 30 transformers 426, 427, by, for example, switching the secondary side of a transformer 426, 427 to ground, thereby creating baluns.

If for example the secondary side of transformer 426 is coupled to ground and the secondary side of transformer 427 is floating the signal at the common RF

17 line port 412 is coupled to the RF signal processing circuitry port 423. If the configurable switching networks 403, 420 are arranged such that the secondary side of the transformer 426 is floating and the secondary side of transformer 427 is coupled to ground, RF signals are coupled between RF signal processing circuitry port 425 and the common RF line port 5 412.

The further advantage is that no external switch is needed to control the coupling, i.e. the RF signal flow. For example, if RF signal processing circuitry 1, 422, comprises a receiving circuit and RF signal processing circuitry 2, 424, comprises a 10 transmit circuit, no external RX/TX switch is needed, since RX/TX diversity is controlled using the configurable switching networks 403, 420 integrated in the IC.

Figure 5 discloses a part of a communication device comprising an IC, and multiple line signal circuits and coupling circuits, wherein the coupling circuits 15 comprise a transmission line, according to an example of the invention.

Here, the part of the communication device 501 comprises an IC 502, having two configurable switching networks 503, 520, each having a configurable switching network port 504, 521. The part of the communication device 501 further 20 comprises two coupling circuits 508, 512, comprising two transmission lines 521, 522 of approximately a quarter-wave length long at the frequency of operation. The line signal circuits 505, 517, also comprise a transmission line 524, 523 connected between the line signal circuit network port 506, 518, and the line signal circuit line port 507, 519.

25 The configurable switching networks 503, 520 may be arranged such that the impedance at the line signal circuit line port is either a short or an open. Based on the setting in the configurable switching networks 503, 520, the common RF port 516, connected to the coupling circuit processing circuitry ports 511, 515, may now be functionally disconnected from either coupling circuit line port 510 or from coupling circuit 30 line port 514.

If the input impedance of line signal circuit line port 519 is a short, the antenna signal is reflected at that port and the antenna connected to coupling circuit line port 514 is not seen at the common RF port 516 due to the impedance inversion of the 18 transmission line integrated in coupling circuit 512, i.e. it is functionally disconnected. If the input impedance of line signal circuit line port 519 is an open, coupling circuit line port 514 is connected to common RF port 516.

5 Likewise if the input impedance of line signal circuit line port 507 is a short, the antenna signal is reflected at that port and the antenna connected to coupling circuit line port 510 is not seen at the common RF port 516 due to impedance inversion of the transmission line integrated in coupling circuit 508. If the input impedance of line signal circuit line port 507 is an open, coupling circuit line port 510 is functionally 10 connected to the common RF port 516.

The transmission line 523, 524 integrated in line signal circuit 505, 517 provides a phase shift, therefore, its length is chosen based on the impedance at the configurable switching network port 504, 521, and such that at the line signal circuit line 15 port 507, 519, the impedance may be a short or an open, based on the setting of the configurable switching network 503, 520.

If the impedance set at the line signal circuit line port 507, 519 is not considered a short or an open, but an impedance causing a significant reflection of the 20 antenna signal, the impedance of the coupling circuit line port 510, 514 is tuned or matched.

Figure 6 discloses a part of a communication device comprising an IC, multiple line signal circuits and coupling circuits, wherein the coupling circuits comprise 25 transformers and transmission lines, according to an example of the invention.

The part of the communication device 601 comprises RF signal processing circuitry 1 (not shown) connected to RF signal processing circuitry port 615 and RF signal processing circuitry 2 (not shown) connected to RF signal processing 30 circuitry port 616. Part of figure 6, indicated by the circuit inside the dashed line 614, is an architecture related to the architecture of figure 4, wherein two coupling circuits 620, 621 and two line signal circuits 622, 623, jointly comprise a transformer, connected with the secondary side to a common RF port 612, connected to coupling circuit processing circuitry ports 611, 613. This RF port 612 forms the input/output for the other part of the 19 figure outside the dashed line 614. The part outside the dashed line is related to an architecture shown in figure 5.

The two coupling circuits 607 and 608 both comprise a quarter lambda 5 transmission line 625, 626. The common RF port 612 is an RF signal processing circuitry port for both coupling circuit circuits 607 and 608.

The line signal circuits 605 and 606 both comprise a transmission line 627, 628 such that the impedance at the coupling circuit line port 609 and 610 may be 10 controlled by the configurable switching networks 603, 604.

If the impedance of the line signal circuit line port 619 is controlled by the configurable switching network 603 to be a short then no power flows between the coupling circuit line port 609 and the RF signal processing circuitry ports. Likewise if the 15 impedance of the line signal circuit line port 618 is set by the configurable switching network 604 to be a short, no power flows between the coupling circuit line port 610 and the RF signal processing circuitry ports. As such the configurable switching networks 603 and 604 implement antenna port diversity, without the need for an external switch.

20 Besides setting the configurable switching networks 603 and 604, such that one of them causes the impedance at the line signal circuit line port 619, 618 to be a short, they can both be set such that the line signal circuit line port 619, 618, is reflective but not a short. Doing so the impedance seen by the RF signal processing circuitries into transceiver RF ports 615, 616 is controlled.

25

The advantage of the architecture shown in figure 6 is that the communication device has no need for external switches while it implements RX/TX selectivity and antenna diversity. A second advantage is that the architecture provides for a method to tune the impedance seen by the RF signal processing circuitries.

30

In the above description and the claims the term connected has to be understood as an electrical connection, either a direct galvanic connection or an electrical connection via one or more electrical components.

20

The present invention is not limited to the embodiments as disclosed above, and can be modified and enhanced by those skilled in the art beyond the scope of the present invention as disclosed in the appended claims without having to apply inventive skills.

5

Claims

A communication device (101), comprising ·. an integrated circuit, IC, (102) with a configurable switch network (112) comprising a configurable switch network port (113); high frequency, RF, signal processing circuits (103) with an RF signal processing circuit port (104) for transmitting RF signals; a coupling circuit (105) with a coupling circuit processing circuit port (106) connected to the RF signal processing circuit port (104), and a coupling circuit line port (107) for communicating RF signals, the coupling circuit (105) being arranged for coupling RF signals between the coupling circuit processing circuit port (106) and the coupling circuit line port (107), characterized in that the communication device (101) further comprises a line signal circuit (109), the line signal circuit (109) being connected to the coupling circuit line port (109) has line signal circuit line port (111), and has a line signal circuit network port (110) connected to the configurable switch network port (113), wherein the line signal circuit (109) is adapted to control, through the configurable switch network (112), the coupling of RF signals between the clutch circuit processing circuit track t (106) and the coupling circuit line port (107).

The communication device (101) of claim 1, wherein the RF signal processing circuits (103) are an RF receiver circuit.

The communication device (101) of claim 1, wherein the RF signal processing circuitry (103) is an RF transmitter circuit. 30

The communication device (101) according to any of the preceding claims, wherein the RF signal processing circuits (103) are integrated into the IC (102) 2005607, and wherein the configurable switching network port (113) and the RF signal processing circuit port (104) are electrically functionally separated.

Communication device (101) according to one of the preceding claims, wherein the line signal circuit (109) and the coupling circuit (105) only comprise electrically passive components.

6. Communication device (101) according to any of the preceding claims, wherein the configurable switching network (112) comprises an electrically controllable switch.

The communication device (101) of claim 6, wherein the switch connects the configurable switch network port (113) with signal ground.

A communication device (101) according to any one of the preceding claims, wherein the coupling circuit (107) and the line signal circuit (109) only comprise components with functionally time-invariant small signal parameters.

The communication device (101) according to any of the preceding claims, wherein the configurable switching network (112) comprises a filter circuit.

10. Communication device (101) according to any of the preceding claims, wherein the configurable switching network (112) comprises a capacitor.

The communication device (101) of claim 10, wherein the capacitor is an electrically configurable capacitor. 30

The communication device (101) according to any of the preceding claims, wherein the configurable switching network (112) comprises a series c *% resonance network.

13. Communication device (101) according to any of the preceding claims, wherein the configurable switching network (112) comprises a parallel resonance network.

A communication device (101) according to any one of the preceding claims, adapted to have an operating frequency above 100 MHz.

The communication device (101) according to any of the preceding claims, wherein the line signal circuit (109) is an impedance transformation circuit.

16. The communication device (101) of claim 15, wherein the line signal circuit (109) comprises a transmission line.

The communication device (101) of claim 16, wherein the transmission line has a length of approximately a quarter of a wavelength for an operating frequency of the communication device. 20

The communication device (101) according to any of the preceding claims, wherein the coupling circuit (105) is an impedance transform circuit.

The communication device (101) of claim 18, wherein the coupling circuit (105) comprises a transmission line.

20. A communication device (101) according to claim 19, wherein the transmission line has a length of approximately a quarter of a wavelength for an operating frequency of the communication device (101).

A communication device (301) according to any one of the preceding claims, wherein the coupling circuit (306) and the line signal circuit (310) together comprise an RF transformation circuit (313) with a primary transformation port and a secondary transformation port, wherein the primary port is coupled to the coupling circuit processing circuit port (307), wherein the secondary conversion port has a first terminal and a second terminal, wherein the first terminal is coupled to the line signal circuit line port (312) and the second terminal to the line signal circuit network port (311) is connected.

The communication device (301) of claim 21, wherein the RF transformation circuit (313) comprises at least two coupled transmission lines.

The communication device (201) according to any of the preceding claims, further comprising: 15. further RF signal processing circuits (222) with a further RF signal processing circuit port (223); a further configurable switch network (220) with a further configurable switch network port (221); a further coupling circuit (213) with a further coupling circuit line port (216) and a further coupling circuit processing circuit port (214); and a further line signal circuit (217) with a further line signal circuit line port (219) and a further line signal circuit network port (218), wherein the further link circuit processing circuit port (214) is connected to the further RF signal processing circuit port (223), the further line signal circuit network port (218) is connected to the further configurable switching network port (221), and wherein the further coupling circuit line port (216) is connected to the further line signal switching line port (219). 30

A communication device (201) comprising a configuration according to claim 23, wherein the coupling circuit line port (211) is connected to the further coupling circuit line port (216).

The communication device (601) according to claim 24, further comprising a third and fourth configurable switching network (603, 604) with a third and fourth configurable switching network port, a third and fourth coupling circuit (607, 608), and a third and fourth fourth coupling circuit line port (609, 610) and a third and fourth coupling circuit processing circuit port (611, 613) and a third and fourth line signal circuit (605, 606) with a third and fourth line signal switching line port (619, 618) and a third and fourth line signal switching network ports, respectively wherein the third line signal switching network port is connected to the third configurable switching network port, the third coupling switching line port (609) being connected to the third line signal switching line port (619), wherein the fourth line signal switching network port is connected to the fourth configurable switching network port, the fourth head circuit line port (610) is connected to the fourth line signal circuit line port (618), the third link circuit processing circuit port (611) being connected to the fourth link circuit processing circuit port (611) and forming a common link circuit processing circuit port (612), and wherein the common link circuit processing circuit port (612) is connected to the coupling circuit line port (107) and the further coupling circuit line port (216).

The communication device (501) according to any of claims 1 to 22, further comprising: further RF signal processing circuitry with a further RF signal processing circuit port; a further configurable switch network (52) with a further configurable switch network port (521); a further coupling circuit (512) with a further coupling circuit line port (514) and a further coupling circuit processing circuit port (515); and a further line signal circuit (517) with a further line signal circuit line port (519) and a further line signal circuit network port (518), wherein the further link circuit processing circuit port (515) is connected to the further RF signal processing circuit port, the further link circuit line port (514) being connected to the further line signal switching line port (519) is connected, wherein the further line signal switching network port (518) is connected to the further configurable switching network port (521), and wherein the RF signal processing circuits and the further RF signal processing circuits form a single RF signal processing circuit with a single RF signal processing circuit port (516) which forms the RF signal processing circuit port and the further RF signal processing circuit port.

The communication device (601) according to any of claims 23 to 25, wherein the further coupling circuit (621) and the further line signal circuit (623) together comprise a further RF transformation circuit with a further primary transformation port and a further secondary transformation port wherein the further primary port is coupled to the further coupling circuit processing circuit port, the further secondary transformation port having a further first terminal and a further second terminal, wherein the further first terminal is coupled to the further line signal circuit line port and the further second terminal to the further line signal switching network port is coupled. 25

The communication device (601) according to claims 25 and 27, wherein the third and fourth link circuit (607, 608) comprise a transmission line and the third and fourth line signal circuit (605, 606) comprise an impedance transform circuit. 30

A communication device (501) according to claim 26, wherein the further coupling circuit (512) comprises a transmission line and the further line signal circuit (517) comprises an impedance transforming circuit.

The communication device (101; 201; 301; 401; 501; 601) according to any of the preceding claims, comprising user interface equipment (114). 5 2005607