RF smart combiner/splitter

• US 6,323,742 B1
• Filed: 10/15/1999
• Issued: 11/27/2001
• Est. Priority Date: 10/15/1999
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Ke, Meng-Kun
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): Glenn, Kimberly E
• Application Number:
  US09/419,450
• Time in Patent Office: 774 Days
• Field of Search: 333/101, 333/103, 333/104, 333/105, 333/125, 333/127, 333/128, 333/136
• US Class Current: 333/127
• CPC Class Codes: H01P 1/10 for switching or interrupting in systems using reflection or reradiation of radio, acoustic or other waves G01S7/034
• CPC Class Codes: H01P 5/12 Coupling devices having more than two ports H01P5/04 takes precedence
• CPC Class Codes: H03F 2200/387 A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier
• CPC Class Codes: H03F 2200/421 Multiple switches coupled in the output circuit of an amplifier are controlled by a circuit
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/60 Amplifiers in which coupling networks have distributed constants, e.g. with waveguide resonators H03F3/54 takes precedence
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers
• CPC Class Codes: H03F 3/72 Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal

Abstract

An impedance transforming device includes a first port capable of receiving first signals. A first switching device is electrically connected to the first port. The first switching device is electrically and dynamically connected to an input of one of at least two impedance transforming devices. A second switching device is electrically and dynamically connected to an output of the impedance transforming device. A second port, electrically connected to the second switching device, is capable of outputting second signals. The impedance transforming device is determined at least as a function of respective impedance transformations of the impedance transforming devices.

Claims

1. A signal combiner, comprising:

a plurality of inputs receiving respective input signals, each of the inputs having a respective input impedance;

first and second transforming devices having respective first and second transforming impedances, one of the transforming devices receiving a transforming device input signal formed from at least one of the input signals, an equivalent impedance being determined as a function of a number of the inputs forming the transforming device input signal;

an output, having an output impedance, electrically connected to the one of the transforming devices, an output signal, which is formed as a function of the transforming device input signal, being produced by the output, the one of the transforming devices matching the equivalent impedance to the output impedance within a tolerance; and

a first switch electrically connected to at least one of the inputs, the first switch also being electrically and selectively connected to the one of the transforming devices.

2. The signal combiner as set forth in claim 1, wherein the respective impedances of the inputs are determined at least as a function of a number of the inputs connected to an electrical ground.

3. The signal combiner as set forth in claim 2, further including:

a third transforming device having a third transforming impedance; and

a fourth transforming device having a fourth transforming impedance, the one of the transforming devices being determined at least as a function of the equivalent impedance and the respective transforming impedances of the four transforming devices;

wherein the plurality of inputs include four inputs receiving four respective input signals;

wherein Z₀ represents respective impedances for each of the four inputs and the output over about one-quarter wavelength;

wherein the first, second, third, and fourth transforming devices have transforming impedances of about Z₀, Z₀/1.4, Z₀/1.7, and Z₀/2.0, respectively, over about one-quarter wavelength; and

wherein one of the first, second, third, and fourth transforming devices, respectively, is the one of the transforming devices when three, two, one, and zero of the inputs, respectively, are connected to the ground.

4. The signal combiner as set forth in claim 2, further including:

a plurality of ground switches for selectively switching the respective inputs between a signal source and the ground; and

a control circuit for selectively controlling the first switch and the ground switches.

5. The signal combiner as set forth in claim 4, wherein the signal source includes respective amplifiers electrically connected to the inputs.

6. The signal combiner as set forth in claim 1, further including:

an electrical connection point electrically connected to the inputs and to the first switch.

7. A signal combiner, comprising:

a plurality of inputs receiving respective input signals, each of the inputs having a respective input impedance;

first and second transforming devices each including a plurality of transformers having respective impedances, one of the transformers in each of the transforming devices receiving a respective transforming device input signal formed from at least one of the input signals, respective equivalent impedances being determined as a function of a number of the inputs forming the transforming device input signals;

an output, having an output impedance, electrically connected to the respective ones of the transformers in each of the transforming devices, an output signal, which is formed as a function of the transforming device input signals, being produced by the output;

a first switch electrically connected to one of the inputs, the first switch also being electrically and selectively connected to the transformer within the first transforming device having an impedance matching the output impedance within an tolerance; and

a second switch electrically connected to another one of the inputs, the second switch also being electrically and selectively connected to the transformer within the second transforming device having an impedance matching the output impedance within an tolerance.

8. A method of matching impedances of radio frequency signals, including:

receiving a first signal at a first input an input signal including the first signal;

determining a chosen impedance transformer at least as a function of an impedance of the first input and respective impedances of at least two impedance transformers;

selectively switching a first switch between the first input and the chosen transformer;

selectively switching a second switch between an output and the chosen transformer; and

receiving an output signal at the output, the output signal having substantially a same power as the input signal.

9. The method of matching impedances as set forth in claim 8, further including:

receiving second, third, and fourth signals at respective second, third, and fourth inputs, the input signal including the first, second, third, and fourth signals;

wherein the determining step includes;

determining the chosen transformer as a function of respective impedances of the four inputs.

10. The method of matching impedances as set forth in claim 9, wherein the determining step includes:

determining a number of the inputs connected to an electrical ground.

11. The method of matching impedances as set forth in claim 10, wherein the determining step includes:

determining the impedance transformer for transforming an impedance of the input signal to substantially match an impedance of the output.

12. The method of matching impedances as set forth in claim 10, further including:

selectively switching at least two grounding switches of the respective inputs between a signal source and the ground.

13. The method of matching impedances as set forth in claim 8, further including:

receiving a second signal at a second input, the input signal including the first and second signals;

determining a second chosen impedance transformer at least as a function of an impedance of the second input and respective impedances of at least two additional impedance transformers;

selectively switching a third switch between the second input and the second chosen transformer; and

selectively switching a fourth switch between the second chosen transformer and the output.

14. An impedance transforming device, comprising:

a first port capable of receiving first signals;

a first switching device electrically connected to the first port;

at least two impedance transforming devices, the first switching device being electrically and dynamically connected to an input of one of the impedance transforming devices;

a second switching device electrically and dynamically connected to an output of the impedance transforming device; and

a second port, electrically connected to the second switching device, capable of outputting second signals, the impedance transforming device being determined at least as a function of respective impedance transformations of the impedance transforming devices.

15. The impedance transforming device as set forth in claim 14, further including:

third, fourth, and fifth ports capable of receiving respective third, fourth, and fifth signals; and

an electrical connection point electrically connected to the first, third, fourth, and fifth ports and to the first switching device.

16. The impedance transforming device as set forth in claim 14, further including:

a third port capable of receiving third signals;

a third switching device electrically connected to the third port;

at least two additional impedance matching devices, the third switching device being electrically and dynamically connected to one of the additional impedance transforming devices;

a fourth switching device electrically and dynamically connected to the additional impedance transforming device; and

an electrical connector electrically connected to the second and fourth switching devices and the second port, the additional impedance transforming device being determined at least as a function of respective impedance transformations of the additional impedance transforming devices.