CN102244505A - Lumped parameter element circuit for RF (radio frequency) chip impedance conversion - Google Patents
Lumped parameter element circuit for RF (radio frequency) chip impedance conversion Download PDFInfo
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- CN102244505A CN102244505A CN2011100795575A CN201110079557A CN102244505A CN 102244505 A CN102244505 A CN 102244505A CN 2011100795575 A CN2011100795575 A CN 2011100795575A CN 201110079557 A CN201110079557 A CN 201110079557A CN 102244505 A CN102244505 A CN 102244505A
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Abstract
The invention discloses a lumped parameter element circuit for RF (radio frequency) chip impedance conversion, comprising a pi-shaped network and a voltage transformation loop module which is formed by connecting an inductance-capacitance circuit with a capacitance-inductance circuit, wherein the inductance-capacitance circuit is an input/output circuit based on inductance; an output end of the inductance-capacitance circuit is connected with an earthed capacitor; the capacitance-inductance circuit is an input/output circuit based on capacitance; an output end of the capacitance-inductance circuit is connected with an earthed inductor; an input end of the pi-shaped network is defined as an input contact of a lumped parameter element; an input of the inductance-capacitance circuit, an input of the capacitance-inductance circuit and an output end of the pi-shaped network in the voltage transformation loop module are connected; output contacts of the inductance-capacitance circuit and the capacitance-inductance circuit are accessed to an RF receiver respectively; and an equivalent load ZL is connected between the two output contacts. By using the lumped parameter element provided by the invention, the signals can be transformed from a differential mode to a single-end mode mutually between the RF receivers and the antenna; and the lumped parameter element circuit is matched with the impedance conversion and integrated with a chip without increasing the size of the chip and the manufacturing cost.
Description
Technical field
The present invention relates to a kind of radio frequency integrated circuit design, relate in particular to a kind of lumped-parameter element circuit that is used for mating on the radio frequency chip impedance conversion between radio-frequency (RF) transceiver and the antenna.
Background technology
In the epoch of current radio communication, radio-frequency (RF) transceiver is widely used as a kind of equipment that receives and send wireless signal, and typical radio-frequency transmitter is to comprise bluetooth, mobile phone wireless LAN or the like.In a typical radio frequency transceiver, there is a reception link (receiver) that is used for received RF signal, also there is a transmitting chain (transmitter) that is used for transmitting radio frequency signal simultaneously.Receive link and transmitting chain and in the period at an interval, open or close, from the antenna received RF signal or to the antenna transmission radiofrequency signal.When from the antenna received RF signal, signal just transfers differential signal to from a single-ended signal, and when to the antenna transmission radiofrequency signal, radiofrequency signal also must be converted into single-ended signal from differential signal.This is because be the cause of single-ended signal form on the wireless system Antenna Design, and in order to suppress background noise, signal transmits in radio-frequency (RF) transceiver or receives common form with differential signal and participates in simultaneously.Therefore, in the radio-frequency communication of radio-frequency (RF) transceiver and antenna, need one with the conversion equipment (abbreviating " transformer " as) of signal, as shown in Figure 1 in difference and single-ended effective conversion.
No matter be accompanied by the format conversion of signal, be to be converted to single-ended signal from differential signal, still is converted to differential signal from single-ended signal, and another critical function of conversion equipment is---impedance conversion.Usually, antenna impedance is designed to 75 Ω or 50 Ω, but the input impedance of receiver value is higher, and the output impedance of transmitter is lower.Generally receive in the link at radio frequency, antenna is to be connected to low noise amplifier (LNA), so that faint input signal amplifies.The input port of this low noise amplifier is typically connected to transistorized gate pole or base stage, therefore has higher input impedance.This input impedance is the above capacitive load of hundreds of ohm, thereby transformer needs to convert antenna impedance (75 Ω or 50 Ω) to this low noise amplifier input impedance (～100 Ω) under receiving mode.Under emission mode, power amplifier will provide antenna a higher power output, and the output impedance of power amplifier is generally tens of ohm capacitive load.Therefore transformer also needs this output impedance (～10 Ω) of power amplifier is transformed into antenna impedance (75 Ω or 50 Ω), to realize to the antenna transmission radiofrequency signal.
Usually, this type of transformer that is used for the radiofrequency signal format conversion can be achieved at certain resolution element, and such resolution element is called Ba Lun.It is not to be incorporated on the radio-frequency (RF) transceiver, therefore is called as the separating chips transformer.This Ba Lun is normally very expensive, and the cost that makes up such Ba Lun is quite high.And this solution also has some other shortcomings.Under the polynary relatively situation of operating frequency, the size of transformer is relatively large, and does not allow such transformer is integrated on the chip.
Summary of the invention
Defective in view of above-mentioned prior art existence, the objective of the invention is to propose a kind of lumped-parameter element circuit that is used for the conversion of radio frequency chip matched impedance, the integration of transformer and lumped-parameter element by overall chipization, the conversion between matched impedance conversion and radiofrequency signal different-format be can realize, and the chip size and the cost cost of radio frequency integrated circuit do not increased.
The technical solution that above-mentioned purpose of the present invention is achieved is: a kind of lumped-parameter element circuit that is used for the conversion of radio frequency chip matched impedance, it is characterized in that: the transformation loop module that described lumped-parameter element comprises pin network and become with appearance inductive circuit associative structure by the LC circuit, wherein said LC circuit is the input/output circuitry based on inductance, its output is connected with the electric capacity of ground connection, described appearance inductive circuit is the input/output circuitry based on electric capacity, and its output is connected with the inductance of ground connection; The input of described pin network is defined as the input contact A of lumped-parameter element, the input of the input of LC circuit in the described transformation loop module, appearance inductive circuit is converged with the output of pin network and is connected to contact B mutually, the output contact D of the output contact C of described LC circuit and appearance inductive circuit inserts radio-frequency (RF) transceiver, and is connected with load ZL between output contact C, D.
Further, the output contact C of described LC circuit is connected with the electric capacity of ground connection and the inductance of ground connection; The output contact D of described appearance inductive circuit is connected with the electric capacity of ground connection and the inductance of ground connection, constitutes the symmetrical expression transformation loop module between contact B, C, D.
The technical solution that above-mentioned purpose of the present invention is achieved can also be: a kind of lumped-parameter element that is used for the conversion of radio frequency chip matched impedance, it is characterized in that: described lumped-parameter element comprises pin network and corrects segmented transformation loop module by the symmetry that two-way LC circuit becomes with two appearance of a street inductive circuit associative structures, wherein said LC circuit has the inductance of series connection more than two, be connected with the electric capacity of ground connection between each inductance, described appearance inductive circuit has the electric capacity of series connection more than two, the inductance that is connected with ground connection between each electric capacity; The input of described pin network is defined as the input contact A of lumped-parameter element, wherein the input of the input of first via LC circuit, first appearance of a street inductive circuit is converged with the output of pin network and is connected to contact B mutually in the transformation loop module, and the output contact C of this first via LC circuit connects the appearance inductive circuit of the second tunnel output ground connection, the output contact D of this first appearance of a street inductive circuit connects the LC circuit of the second tunnel output ground connection, described output contact C and output contact D insert radio-frequency (RF) transceiver, and are connected with load ZL between output contact C, D.
A kind of lumped-parameter element circuit that is used for the radio frequency chip impedance conversion of the present invention, its outstanding effect is:
By using the lumped-parameter element of this kind bulk provided by the invention, between radio-frequency (RF) transceiver and antenna, can realize the conversion process of signal at difference and single-ended two kinds of forms, and matched impedance conversion in this course, eliminated expensive and the Ba Lun that can't be integrated of trace utilization cost; Same this lumped-parameter element can be integrated among the chip of radio frequency integrated circuit, and does not increase the size and the manufacturing cost of chip.
Description of drawings
Fig. 1 is the typical radio-frequency receive-transmit system electrical block diagram that contains Ba Lun on the traditional die;
Fig. 2 the has been integrated radio-frequency system electrical block diagram of lumped-parameter element of the present invention;
Fig. 3 a and Fig. 3 b are respectively LC circuit and the basic structure schematic diagram that holds inductive circuit;
Fig. 4 is by the LC circuit and holds the electrical block diagram that the inductive circuit connection constitutes lumped-parameter element;
Fig. 5 a and Fig. 5 b are based on the changes in amplitude curve of lumped-parameter element circuit shown in Figure 4 and the phase place curve with frequency change;
Fig. 6 is that lumped-parameter element shown in Figure 4 is realized the electrical schematic diagram that conversion of signals and matched impedance change;
Fig. 7 is the derivation embodiment circuit diagram that lumped-parameter element shown in Figure 6 is realized function;
Fig. 8 is the enforcement sketch that lumped-parameter element shown in Figure 4 is applied to the 2.5GHz radio-frequency (RF) transceiver;
Fig. 9 a and Fig. 9 b are based on input coupling and the output match curve of lumped-parameter element shown in Figure 8 in the simulation of 2.5GHz radio band;
Figure 10 a and Figure 10 b are based on the changes in amplitude curve of lumped-parameter element circuit shown in Figure 6 and the phase place curve with frequency change;
Figure 11 is based on the amplitude of lumped-parameter element circuit shown in Figure 6 and the phase place change curve with time domain;
Figure 12 is the sketch of another embodiment symmetrical expression transformation loop module of lumped-parameter element of the present invention;
The symmetrical expression transformation loop module shown in Figure 12 that is based on Figure 13 realizes the schematic diagram of impedance input coupling;
Figure 14 is based on the amplitude of lumped-parameter element circuit shown in Figure 12 and the phase place change curve with frequency domain;
Figure 15 is based on the amplitude of lumped-parameter element circuit shown in Figure 12 and the phase place change curve with time domain;
Figure 16 is the enforcement sketch that lumped-parameter element shown in Figure 6 is applied to the 1.25GHz radio-frequency (RF) transceiver;
Figure 17 a to Figure 17 d is based on the schematic diagram that lumped-parameter element shown in Figure 16 is realized impedance input coupling;
Figure 18 is that the present invention adopts the appearance inductive circuit of more piece symmetry and the lumped-parameter element of LC circuit formation to realize the circuit diagram that impedance matching and signal format are changed.
Embodiment
Following constipation closes the embodiment accompanying drawing, the specific embodiment of the present invention is described in further detail, so that technical solution of the present invention is easier to understand, grasp.
Compare to the typical radio-frequency receive-transmit system electrical block diagram that contains Ba Lun on the traditional die of describing in the background technology, see also Fig. 2 and contrast in Fig. 1, the radio-frequency system circuit structure of as seen integrated lumped-parameter element of the present invention is more succinct, consider outside the attainable function, can realize easily that chipization is integrated.And in fact, the lumped-parameter element in this circuit between radio-frequency (RF) transceiver and the antenna removes the conversion that can realize two kinds of forms of radiofrequency signal, can also the matched impedance conversion.
Following constipation closes circuit diagram, on principle the present invention is carried out detailed inference, displaying.
LC electrical block diagram shown in Fig. 3 a, it is the input/output circuitry based on inductance, its output is connected with the electric capacity of ground connection.The input/output relation of this circuit is as follows:
Wherein ω is an angular frequency;
Appearance inductive circuit structural representation shown in Fig. 3 b, it is the input/output circuitry based on electric capacity, its output is connected with the inductance of ground connection.The input/output relation of this circuit is as follows:
As shown in Figure 4, be to hold inductive circuits and LC circuit with above-mentioned two to combine and constitute the electrical block diagram of lumped-parameter element.What notice is to work as
The time, V
Out1Equal V
Out2, and the skew of existing 180 ° of both phase places, shown in Fig. 5 a and Fig. 5 b.
If consider V
Out=V
Out1-V
Out2As a differential signal, that just can draw a conclusion: when
Single-ended input signal V
InBe converted into that amplitude is identical, the output signal V of the difference of 180 ° of phase differences
Out
In addition, can consider input impedance and output impedance a part, electrical schematic diagram as shown in Figure 6 as lumped-parameter element.Impedance relationship is as follows:
Figure 10 a and Figure 10 b show based on the changes in amplitude curve of lumped-parameter element circuit shown in Figure 6 and the phase place curve with frequency change; And Figure 11 shows the amplitude of this lumped-parameter element circuit and the phase place change curve with time domain.
Up to now, all calculating and inference all are based on inductance, the capacitor model under the perfect condition, the influence of parasitism are not included among the thinking as yet.But in fact, the inductance of any lumped-parameter element always exists parasitic capacitance and spurious impedance, and in order to compensate or offset this kind parasitic effects, a kind of general pin network is proposed and participates in that matched impedance changes and differential-to-single-ended.Wherein this pin network can be to hold the sense combined circuit according to different needs, or is reduced to an independent inductance or electric capacity, as shown in Figure 7.This kind is used for the lumped-parameter element of radio frequency chip matched impedance conversion, the transformation loop module that comprises pin network and become with appearance inductive circuit associative structure by the LC circuit, wherein the input of pin network is defined as the input contact A of lumped-parameter element, the input of the input of LC circuit in the described transformation loop module, appearance inductive circuit is converged with the output of pin network and is connected to contact B mutually, the output contact D of the output contact C of described LC circuit and appearance inductive circuit inserts radio-frequency (RF) transceiver, and is connected with load Z between output contact C, D
L
In order to overcome the many influences under the aforementioned nonideality, another kind of symmetrical expression transformation loop module just is suggested, as shown in figure 12.On lumped-parameter element circuit base shown in Figure 6, the output contact C of LC circuit is connected with the electric capacity of ground connection and the inductance of ground connection; And the output contact D of former appearance inductive circuit is connected with the electric capacity of ground connection and the inductance of ground connection, constitutes the symmetrical expression transformation loop module between contact B, C, D.
In fact, the current flux of two branches of lumped-parameter element circuit shown in Figure 6 is different.Be this otherness of balance, a high pass branch that is made of serial capacitor C 2 and inductance L 3 in parallel with it need be provided, join with low pass branch (LC circuit) shown in Figure 6; Similarly, provide a low pass branch equally, join, make this lumped-parameter element circuit symmetrical balance on the whole thus with high pass branch (appearance inductive circuit) shown in Figure 6.This low pass branch and high pass branch redundancy can be filled up matching frequency response, present the impedance of a balance in the full frequency-domain scope, thereby realize more balance, a stable amplitude and a phase place.
As checking: symmetrical expression transformation loop module shown in Figure 12 is designed to carry out in the frequency 2.5GHz radio-frequency receiving-transmitting.This loop modular circuit can convert the load impedance of 300 Ω to 50 Ω, and has converted differential signal to single-ended signal simultaneously, and its equivalent oscillogram such as Figure 13 are to shown in Figure 15.Figure 13 shows that the schematic diagram of realizing impedance input coupling based on Figure 12 symmetrical expression transformation loop module, when comparing to the employing symmetrical structure in the diagram, S11 is lower than-10dB, and has a wideer frequency range.Figure 14 and Figure 15 are respectively the amplitude of lumped-parameter element circuit and phase place with the change curve of frequency domain and amplitude and the phase place change curve with time domain.As seen adopted behind the symmetrical structure, can obtain the more stable differential signal of amplitude and phase place.
Embodiment one
As shown in Figure 8, be according to the present invention's design rule shown in Figure 4, the lumped-parameter element that is applied to the 2.5GHz radio-frequency (RF) transceiver is implemented sketch; It will convert the load impedance of 300 Ω to 50 Ω, and realize the conversion of differential signal to single-ended signal simultaneously.Fig. 9 a and Fig. 9 b are based on input coupling and the output match curve of lumped-parameter element shown in Figure 8 in the simulation of 2.5GHz radio band.
Embodiment two
As shown in figure 16, be according to the present invention's design rule shown in Figure 4, the lumped-parameter element that is applied to the 1.25GHz radio-frequency (RF) transceiver is implemented sketch; It will convert the load impedance of 400 Ω to 50 Ω, and realize the conversion of differential signal to single-ended signal simultaneously.Figure 17 a to Figure 17 d is based on input coupling and the output match curve of lumped-parameter element shown in Figure 16 in the simulation of 1.25GHz radio band.Illustrated analog equivalent result is as seen: near the 1.25GHz frequency range, S11 and S22 all-below the 10dB, the equivalent resistance that shows input is near 50 Ω, and the equivalent resistance of output is near 400 Ω.As seen, in the 1.25GHz frequency range, can access the more stable differential signal of amplitude and phase place.
Embodiment three
In order further to improve branch's degree of balance and to increase the scope that can implement frequency domain, the present invention also provides employing more piece symmetry LC, appearance sense lumped-parameter element circuit to realize matched impedance conversion and the single-ended radiofrequency signal conversion of difference commentaries on classics, as shown in figure 18.
This lumped-parameter element comprises pin network and corrects segmented transformation loop module by the symmetry that two-way LC circuit becomes with two appearance of a street inductive circuit associative structures, wherein said LC circuit has the inductance of series connection more than two, be connected with the electric capacity of ground connection between each inductance, described appearance inductive circuit has the electric capacity of series connection more than two, the inductance that is connected with ground connection between each electric capacity; The input of described pin network is defined as the input contact A of lumped-parameter element, wherein the input of the input of first via LC circuit, first appearance of a street inductive circuit is converged with the output of pin network and is connected to contact B mutually in the transformation loop module, and the output contact C of this first via LC circuit connects the appearance inductive circuit of the second tunnel output ground connection, the output contact D of this first appearance of a street inductive circuit connects the LC circuit of the second tunnel output ground connection, described output contact C and output contact D insert radio-frequency (RF) transceiver, and are connected with load Z between output contact C, D
L
Claims (3)
1. lumped-parameter element circuit that is used for the radio frequency chip impedance conversion, it is characterized in that: the transformation loop module that described lumped-parameter element circuit comprises pin network and become with appearance inductive circuit associative structure by the LC circuit, wherein said LC circuit is the input/output circuitry based on inductance, its output is connected with the electric capacity of ground connection, described appearance inductive circuit is the input/output circuitry based on electric capacity, and its output is connected with the inductance of ground connection; The input of described pin network is defined as the input contact A of lumped-parameter element circuit, the input of the input of LC circuit in the described transformation loop module, appearance inductive circuit is converged with the output of pin network and is connected to contact B mutually, the output contact D of the output contact C of described LC circuit and appearance inductive circuit inserts radio-frequency (RF) transceiver, and is connected with load ZL between output contact C, D.
2. a kind of lumped-parameter element circuit that is used for the radio frequency chip impedance conversion according to claim 1, it is characterized in that: the output contact C of described LC circuit is connected with the electric capacity of ground connection and the inductance of ground connection; The output contact D of described appearance inductive circuit is connected with the electric capacity of ground connection and the inductance of ground connection, constitutes the symmetrical expression transformation loop module between contact B, C, D.
3. lumped-parameter element circuit that is used for the radio frequency chip impedance conversion, it is characterized in that: described lumped-parameter element circuit comprises pin network and corrects segmented transformation loop module by the symmetry that two-way LC circuit becomes with two appearance of a street inductive circuit associative structures, wherein said LC circuit has the inductance of series connection more than two, be connected with the electric capacity of ground connection between each inductance, described appearance inductive circuit has the electric capacity of series connection more than two, the inductance that is connected with ground connection between each electric capacity; The input of described pin network is defined as the input contact A of lumped-parameter element, wherein the input of the input of first via LC circuit, first appearance of a street inductive circuit is converged with the output of pin network and is connected to contact B mutually in the transformation loop module, and the output contact C of this first via LC circuit connects the appearance inductive circuit of the second tunnel output ground connection, the output contact D of this first appearance of a street inductive circuit connects the LC circuit of the second tunnel output ground connection, described output contact C and output contact D insert radio-frequency (RF) transceiver, and are connected with load ZL between output contact C, D.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100795575A CN102244505A (en) | 2011-03-31 | 2011-03-31 | Lumped parameter element circuit for RF (radio frequency) chip impedance conversion |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100795575A CN102244505A (en) | 2011-03-31 | 2011-03-31 | Lumped parameter element circuit for RF (radio frequency) chip impedance conversion |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1445926A (en) * | 2002-03-15 | 2003-10-01 | 松下电器产业株式会社 | Balance high frequency device, method for improving balance characteristic and balance high frequency circuit using the device |
| CN1930776A (en) * | 2004-03-16 | 2007-03-14 | 日立金属株式会社 | High-frequency circuit and high-frequency component |
| US20100109800A1 (en) * | 2007-08-23 | 2010-05-06 | Fujitsu Limited | Duplexer, communication module, and communication device |
-
2011
- 2011-03-31 CN CN2011100795575A patent/CN102244505A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1445926A (en) * | 2002-03-15 | 2003-10-01 | 松下电器产业株式会社 | Balance high frequency device, method for improving balance characteristic and balance high frequency circuit using the device |
| CN1930776A (en) * | 2004-03-16 | 2007-03-14 | 日立金属株式会社 | High-frequency circuit and high-frequency component |
| US20100109800A1 (en) * | 2007-08-23 | 2010-05-06 | Fujitsu Limited | Duplexer, communication module, and communication device |
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Application publication date: 20111116 |