CN113739931B - Radiometer based on zero reflection network - Google Patents
Radiometer based on zero reflection network Download PDFInfo
- Publication number
- CN113739931B CN113739931B CN202111005346.7A CN202111005346A CN113739931B CN 113739931 B CN113739931 B CN 113739931B CN 202111005346 A CN202111005346 A CN 202111005346A CN 113739931 B CN113739931 B CN 113739931B
- Authority
- CN
- China
- Prior art keywords
- impedance
- radiometer
- stage
- network
- band
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000003321 amplification Effects 0.000 claims abstract description 46
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 46
- 239000003990 capacitor Substances 0.000 claims description 10
- 230000005540 biological transmission Effects 0.000 claims description 8
- 230000001131 transforming effect Effects 0.000 claims description 4
- 238000001514 detection method Methods 0.000 abstract description 7
- 230000035945 sensitivity Effects 0.000 abstract description 3
- 238000010521 absorption reaction Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 8
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 230000005855 radiation Effects 0.000 description 4
- 229910052710 silicon Inorganic materials 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 238000002955 isolation Methods 0.000 description 3
- 238000004088 simulation Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 230000002452 interceptive effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/0003—Radiation pyrometry, e.g. infrared or optical thermometry for sensing the radiant heat transfer of samples, e.g. emittance meter
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Amplifiers (AREA)
Abstract
The invention discloses a radiometer based on a zero reflection network, which comprises: a multi-stage low noise amplifier and a zero reflection network; the multistage low noise amplifier includes: the N cascaded single-stage low-noise amplification units are sequentially marked as a first-stage low-noise amplification unit, a … …, an ith-stage low-noise amplification unit, a … … and an Nth-stage low-noise amplification unit and are used for amplifying a radio frequency input signal, and the zero reflection network is used for matching the output impedance of the multi-stage low-noise amplifier and absorbing an out-of-band reflection signal to realize no-reflection signal at a port; the mixer can be arranged at the last stage of the heterodyne radiometer based on the zero reflection network; the detector can be arranged at the last stage of the direct-detection radiometer based on the zero-reflection network. The invention improves the linearity, sensitivity and stability of the radiometer system and reduces the circuit size by introducing the zero reflection network.
Description
Technical Field
The invention belongs to the technical field of radiometers, and particularly relates to a radiometer based on a zero reflection network and a derivative framework thereof.
Background
Radiometers are devices designed for the radiation characteristics of objects, and receive thermal radiation from the environment for detection and imaging. The heterodyne architecture and the direct detection architecture are widely used in the design of radiometers, the former mainly consists of a multi-stage Low Noise Amplifier (LNA) and a mixer, and the latter mainly consists of a multi-stage low noise amplifier and a detector. The maturity of silicon technology makes fully integrated, high performance millimeter wave radiometers possible, which can be used in V-band, W-band and even higher frequency bands. Typically, the ambient radiation signal is about-90 dBm, and the millimeter wave radiometer detects in the form of a large number of array elements, which places high demands on the sensitivity and dynamic range of the radiometer. However, the interstage signal reflection of each module in the radiometer can lead active devices such as an amplifier, a mixer and a detector to introduce extra intermodulation signals, increase gain fluctuation, reduce the dynamic range of the whole radiometer system and even cause internal self-excitation to cause abnormal work. Reducing interstage signal reflections from modules in the radiometer is therefore an effective means to improve stability and linearity.
Here, taking the heterodyne radiometer as an example, in order to reduce the interstage reflection, the conventional heterodyne radiometer architecture mainly has the following three types:
(1) As shown in fig. 1, a circulator is added between the multistage low noise amplifier and the mixer, and a forward signal is transmitted through the circulator, while a reflected signal generated at an input end surface of the mixer is absorbed by the circulator. However, due to the limitation of the process, the circulator cannot be integrated through silicon substrate, and the structure can be realized only by adopting a hybrid integration mode, so that the size and the power consumption of the system are increased;
(2) As shown in fig. 2, a silicon-based integrated attenuator is added between the multi-stage low noise amplifier and the mixer, the inter-stage reflected signal is absorbed by the attenuator to improve the isolation, but the attenuator also attenuates the forward wave at the same time, so that the system gain is inevitably reduced by the architecture, and the sensitivity of the overall system is not obviously improved or even deteriorated.
(3) As shown in fig. 3, a set of multi-stage low noise amplifiers is added, quadrature couplers are added before and after the two sets of multi-stage low noise amplifiers to form a balanced amplifier structure, and reflected signals from the amplifiers and the mixers pass through the quadrature couplers and are cancelled at a radio frequency input end, so that the reflected signals are reduced. However, the bandwidth of the quadrature coupler is limited, so the structure has the problems of narrow absorption bandwidth of the reflected signal, large circuit size, large power consumption and the like due to the introduction of the quadrature coupler.
The above is also applicable to the conventional direct-detection radiometer, and the mixer may be replaced with a detector.
In summary, the conventional radiometer is limited by device performance or circuit structure in reducing interstage reflection, and has the problems of narrow absorption bandwidth of reflected signals, reduced gain, incomplete integration, large circuit size, high power consumption and the like.
Disclosure of Invention
Aiming at the defects and the improvement requirements of the prior art, the invention aims to provide a radiometer based on a zero reflection network, and aims to solve the problems that the existing radiometer is limited by device performance or circuit structure in the technology of reducing interstage reflection, the absorption bandwidth of a reflection signal is narrow, the gain is reduced, the radiometer cannot be fully integrated, the circuit size is large or the power consumption is high, and the stability and the linearity of a system are further improved.
The invention provides a radiometer based on a zero reflection network, which comprises: a multi-stage low noise amplifier and a zero reflection network; the multistage low noise amplifier includes: the system comprises N cascaded single-stage low-noise amplification units, a zero reflection network and a signal processing unit, wherein the N cascaded single-stage low-noise amplification units are sequentially marked as a first-stage low-noise amplification unit, a … …, an ith-stage low-noise amplification unit, a … … and an Nth-stage low-noise amplification unit and are used for amplifying a radio frequency input signal, the zero reflection network is used for matching the output impedance of the multistage low-noise amplifier, and an out-of-band reflection signal is absorbed to realize no-reflection signal at a port; wherein N represents the number of the single-stage low-noise amplification units, i represents the serial number of the single-stage low-noise amplification units, N is an integer greater than or equal to 2, and i is greater than or equal to 1 and less than or equal to N.
In the invention, the zero reflection network is used as an output impedance matching network of the multi-stage low noise amplifier and is also used as a reflection signal absorption network to absorb the reflection signal generated by the rear-stage mixer, thereby improving the stability and the linearity of front and rear-stage devices. And the multistage low noise amplifier is formed by cascading N single-stage low noise amplification units, and can provide enough high gain for a link.
The zero reflection network is a passive network, adopts a simple lumped element and transmission line structure, can be integrated on a silicon substrate compared with a circulator and an attenuator, has small circuit size and low loss, and avoids the reduction of system gain. In addition, the zero reflection network not only matches the in-band impedance, but also absorbs the out-of-band reflection signal to realize that the port has no reflection signal.
Furthermore, the zero reflection network is connected to the output end of the Nth-stage low-noise amplification unit and is used for matching in-band impedance and absorbing out-of-band reflection signals, so that the stability and the linearity of the front-stage low-noise amplifier are improved, and the conversion gain of the rear-stage mixer is increased.
Furthermore, the zero reflection network is arranged between any two low-noise amplification units in the N single-stage low-noise amplification units; the zero reflection network is used as an output matching network or an input matching network of the single-stage low-noise amplifier to form the zero reflection low-noise amplifier, and absorbs a reflection signal from a rear-stage circuit or a front-stage circuit.
In the embodiment of the invention, the zero reflection network can select different positions, and the heterodyne radiometer architecture based on the zero reflection network and the direct detection radiometer architecture based on the zero reflection network have N forms respectively.
Furthermore, the radiometer includes M zero-reflection networks, which are respectively marked as a first zero-reflection network, a second zero-reflection network, … … and an M zero-reflection network, wherein any zero-reflection network can be added after the nth stage low noise amplifier unit or between the ith and (i + 1) th stage low noise amplifiers, and there can be 2 N -1 derivative architecture. The zero reflection network is used for replacing each traditional interstage 50 omega matching network, so that the interstage reflection can be eliminated, and the stability and the linearity of the system are further improved; wherein M is more than or equal to 1 and less than or equal to N, and i is more than or equal to 1 and less than or equal to N-1.
Still further, the zero reflection network comprises: the L-stage matching circuit is sequentially connected in series, and the resistive element is connected with the L-stage matching circuit in parallel; the matching circuit is used for converting the input complex impedance into a parallel impedance value of a port impedance and a resistive element in a pass band and converting the parallel impedance value into a value approaching infinity in a stop band; the resistive element is used for further transforming infinite impedance generated outside the band into a matching state and dissipating absorbed reflected signals, the resistance value of the resistive element is selected near the impedance value of the output port, and the impedance approaching the infinite impedance outside the band is matched to the impedance of the output port through parallel connection, so that the output port has no reflected signals in the full frequency band; wherein, L represents the number of the matching circuits and takes the value of a positive integer which is more than or equal to 1.
Wherein, the matching circuit includes: a matching unit arranged at the front stage, and an impedance converter arranged at the rear stage and multiplexed; the matching unit is used for realizing complex impedance matching in a passband; the impedance transformer is multiplexed and generates an out-of-band tending infinite impedance that is transformed to a matched state by the resistive element and dissipates the absorbed reflected signal by the resistive element.
Furthermore, the impedance transformer is implemented by a series capacitor or a series capacitor with a coupled transmission line open at both ends.
Further, the radiometer may be classified into a heterodyne radiometer and a direct sensing radiometer, and when the radiometer is a heterodyne radiometer, the above-described structure further includes a mixer, which is located at the last stage of the radiometer, for mixing the amplified radio frequency signal and the local oscillator signal and outputting an intermediate frequency signal. When the radiometer is a direct-detection radiometer, the structure described above further includes a detector, which is located at the last stage of the radiometer and is used for converting the amplified radio-frequency signal into a direct-current signal and outputting the direct-current signal.
Further, in the heterodyne radiometer architecture based on the zero reflection network, the zero reflection network may be located between the multi-stage low noise amplifier and the mixer, i.e., after the nth stage low noise amplification unit, or may be located between the multi-stage low noise amplifier stages, i.e., between the ith stage and the (i + 1) th stage low noise amplifier; the zero reflection network can replace the traditional 50 omega matching network and be used as an output matching network or an input matching network of a single-stage low-noise amplifier to form the zero reflection low-noise amplifier and absorb a reflection signal from a post-stage circuit or a front-stage circuit; the direct detection type radiometer based on the zero reflection network has the same structure. Wherein i is more than or equal to 1 and less than or equal to N-1.
Compared with the prior art, the technical scheme of the invention can achieve the following beneficial effects:
(1) The zero reflection network provided by the invention is a passive network, is composed of a concentration element and a transmission line structure, and is easier to integrate, smaller in circuit size and lower in power consumption compared with a circulator, an attenuator and an orthogonal coupler.
(2) The zero reflection network is seamlessly integrated in the radiometer, the zero reflection low-noise amplifier can be directly used as an output matching network of a front-stage amplification unit or an input matching network of a rear-stage amplification unit to form the zero reflection low-noise amplifier, an additional 50 omega matching network is not required to be added for interstage matching, the circuit size and the loss are further reduced, and the gain of the whole radiometer system is improved.
(3) The radiometer provided by the invention adopts the zero reflection network as the matching network and the undersea network, realizes in-band impedance matching and out-of-band reflection signal absorption, increases the bandwidth for absorbing interstage reflection signals, covers the full wave band in the absorption range, greatly enhances the linearity and stability of front and rear active devices, and does not increase extra noise coefficient, thereby improving the stability and dynamic range of the whole radiometer system.
Drawings
FIG. 1 is a diagram of a prior art heterodyne radiometer architecture based on a ferrite circulator;
FIG. 2 is a diagram of a prior art attenuator-based heterodyne radiometer architecture;
FIG. 3 is a diagram of a heterodyne radiometer architecture for a prior art quadrature coupler;
FIG. 4 is a diagram of a heterodyne radiometer architecture based on a zero reflection network according to the present invention;
FIG. 5 is a block diagram derived from the heterodyne radiometer architecture based on the zero reflection network as an output matching network of any stage of amplification unit according to the present invention;
FIG. 6 is an architecture diagram derived from the heterodyne radiometer architecture proposed by the present invention based on a zero reflection network as an input matching network for any stage of amplification unit;
FIG. 7 is a block diagram derived from the heterodyne radiometer architecture based on zero reflection networks according to the present invention, wherein more than one zero reflection network is used as the output matching network for multiple amplifying units;
FIG. 8 is a possible zero reflection network architecture proposed by the present invention;
FIG. 9 is a simulation result of S-parameters of a zero reflection network as an output matching network for a multi-stage low noise amplifier;
FIG. 10 is | | c out |-r out | a calculation result diagram of the pass band and the stop band;
FIG. 11 is a graph of the effect of harmonic amplitude on radiometer linearity.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Fig. 4 is a heterodyne radiometer based on a zero reflection network, which belongs to one of the radiometer architectures based on the zero reflection network proposed in the present invention, and includes: the system comprises a multistage low noise amplifier, a zero reflection network and a mixer;
the multistage low noise amplifier includes: the N cascaded single-stage low-noise amplification units are sequentially marked as a first-stage low-noise amplification unit, a … …, an ith-stage low-noise amplification unit, a … … and an Nth-stage low-noise amplification unit and are used for amplifying a radio frequency input signal and providing sufficient gain for a system link;
wherein N represents the number of the single-stage low-noise amplification units, i represents the serial number of the single-stage low-noise amplification units, N is an integer greater than or equal to 2, and i is greater than or equal to 1 and less than or equal to N
The single-stage low noise amplifier comprises an input matching network and an amplifying unit, wherein the inter-stage matching network adopts a traditional 50 omega matching network and is used for matching in-band input impedance.
The zero reflection network includes: the L-stage matching circuit is sequentially connected in series, and the resistive element is connected with the L-stage matching circuit in parallel; the matching circuit is used for converting the complex impedance of the output end of the low-noise amplification unit into a parallel impedance value of the port impedance and the resistive element in a pass band and converting the complex impedance into a parallel impedance value approaching infinity in a stop band; the resistive element is used for further converting infinite impedance generated outside a band into a matching state and dissipating absorbed reflected signals, the resistance value of the resistive element is selected near the impedance value of the output port, and the impedance approaching infinite outside the band is matched to the impedance of the output port through parallel connection, so that the output port has no reflected signals in the full frequency band; wherein, L represents the number of the matching circuits and takes the value of a positive integer which is more than or equal to 1.
The zero reflection network is used as an output matching network of the multi-stage low noise amplifier and connected to the output end of the Nth-stage low noise amplification unit, in-band impedance can be matched, and out-of-band reflection signals from a rear-stage mixer are absorbed, so that introduction of intermodulation products is reduced, gain fluctuation is reduced, stability and linearity of the low noise amplifier and the mixer are improved, and conversion gain of the mixer is improved.
In an embodiment of the present invention, a matching circuit includes: a matching unit arranged at the front stage, and an impedance converter arranged at the rear stage and multiplexed; the matching unit is used for realizing complex impedance matching in a passband; the impedance transformer is multiplexed and produces out-of-band an impedance tending to infinity, which is transformed to a matched state by the resistive element, and the absorbed reflected signal is dissipated by the resistive element.
The matching circuit matches the complex impedance in the passband to the parallel resistance value of the output port impedance and the resistive element to realize the impedance matching of the signal in the passband.
Specifically, the matching circuit can select a structure of serially connecting a capacitor behind a parallel grounding microstrip transmission line or serially connecting a capacitor behind a series inductor to realize each stage of matching according to the numerical values of the input complex impedance under different frequencies.
As an embodiment of the present invention, the impedance transformer may be implemented by a series capacitor or a series capacitor with a capacitive structure of a coupled transmission line with open ends.
The impedance converter simultaneously determines the impedance of the in-band signal and the out-of-band signal, and the capacitance value of the impedance converter meets the requirement of enabling the out-of-band impedance to be infinite and simultaneously ensures impedance matching in a passband.
In the embodiment of the invention, the mixer is positioned at the last stage of the heterodyne radiometer architecture based on the zero reflection network, and mixes a Radio Frequency (RF) signal and a Local Oscillator (LO) signal to output an Intermediate Frequency (IF) signal.
Further, as shown in fig. 5 and fig. 6, the zero reflection network may replace the conventional 50 Ω interstage matching network, and directly serve as an input matching network or an input matching network of the ith-stage amplification unit to form an ith-stage low noise amplifier, i.e., a zero reflection low noise amplifier.
Further, zero reflection networksMore than one zero reflection network may be included, as shown in fig. 7, and are respectively disposed at the output ends of the low noise amplification units. Any zero reflection network can be arranged between the Nth-stage low noise amplification unit or the ith-stage low noise amplification unit and the (i + 1) th-stage low noise amplification unit in common (2) N -1) a derivative architecture; wherein M is more than or equal to 1 and less than or equal to N, and i is more than or equal to 1 and less than or equal to N-1. The output matching network of any amplifying unit is replaced by a zero reflection network to form a zero reflection low noise amplifier. The zero reflection network is simultaneously used as a reflection signal absorption network to absorb reflection signals from a rear-stage low-noise amplifier and a mixer, and can also play a role in improving the stability and linearity of the device, so that the stability and dynamic range of the whole radiometer system are improved.
In order to better illustrate the performance advantages of the radiometer based on the zero reflection network, the circuit architecture is shown in fig. 4, which mainly takes the V-band heterodyne radiometer based on the zero reflection network provided by the present invention as an example, and analyzes and illustrates the expansion of the absorption bandwidth by the zero reflection network and the improvement of the stability and linearity of the radiometer.
The structure of the zero reflection network provided by the invention is shown in fig. 8 and is composed of an in-band matching network and a reflection absorption network, wherein the in-band matching network comprises two stages of matching circuits and a series transmission line TL R1 And a series capacitor C R1 Forming a first stage, parallel transmission line TL R2 And series capacitor CR 2 And the second stage is formed and is used for replacing a traditional 50-omega output matching network and carrying out in-band impedance matching on the front-stage low-noise amplifier. In addition, the series capacitor CR of the second stage 2 Meanwhile, in a reflection absorption network, the out-of-band impedance is converted into infinite, and a parallel connection dissipative resistor R is combined A And full-band matching is realized, so that reflected signals of the port can be eliminated. S parameter simulation is carried out on the zero reflection network, and a simulation result is shown in fig. 9, so that the out-of-band return loss S22 is smaller than-20 dB and the in-band return loss is smaller than-10 dB in a frequency range of 0-110GHz, that is, all frequency bands are in an impedance matching state, reflection signals at an output port are all absorbed, and the absorption bandwidth reaches more than 110 GHz.
Analysis from stability aspect, the output echo reflection S of the conventional LNA due to mismatch in the stop band 22 This leads to a reduction in stability and a tendency to cause problems such as low-frequency oscillation. The zero reflection network without bandwidth limitation is used as an output matching circuit of the low noise amplifier, and multiple reflection signals from the rear-stage frequency mixer can be absorbed in the full frequency band to obtain S which is matched in the full frequency band 22 And absolute stability is realized. Therefore, for low noise amplification based on zero reflection network, when S 22 =0, input end echo reflection | S 11 |<1, the formula of its output stability circle can be expressed as:
c out and r out Respectively representing the center and radius of the output stability circle. For in-band signals, | S due to reverse isolation of the amplifier 12 Is greater than the forward gain | S 21 Such that c out |-r out If is greater than 1, the absolute stability condition is satisfied, whereas for out-of-band signals, due to S 21 Attenuation of | | c out |-r out I is also larger than 1, and an absolute stability condition is satisfied, so that absolute stability can be realized in the full frequency band. More specifically, a typical set of low noise S parameters may be taken as an example, assuming reverse isolation S 12 Is-30 dB, in-band S 11 Is-10 dB, out-of-band S 11 Is-0.1 dB, in-band gain S 21 20dB, out-of-band S 21 Is-10 dB, when the output is no reflection, i.e. S 22 =0, fig. 10 gives the calculated | | c out |-r out And the result graph shows that the result graph is absolutely stable in the full frequency band. On the other hand, the stability of the later mixer is also enhanced due to the cancellation of the reflected signal. According to the formula of the reflection coefficient of the output port of the mixer
It can be known that when the input port has no reflected signal, the gamma in the formula s-mix Can be regarded as 0, therefore, the formula can be further simplified to
Due to 0<|S 22 RF -mix |<1, therefore, the output reflection coefficient of the mixer is always less than 1, and the absolute stability condition is met.
From the linearity analysis, for the heterodyne radiation architecture, assuming that an out-of-band sinusoidal interference signal is input simultaneously with the desired sinusoidal RF signal, amplified by the low noise amplifier, and then enters the mixer, the final output IF signal can be expressed as:
wherein alpha is i (i =1,2,3) represents the nonlinear coefficient, a RF And A INT Representing the voltage amplitude, omega, of the RF signal and of the interfering signal, respectively RF And omega INT Representing the frequencies of the RF signal and the interfering signal, respectively. Further, an input power 1dB compression point formula of the radiometer system can be obtained
As can be seen from the equation, IP1dB decreases with increasing interferer amplitude, indicating that system linearity deteriorates with increasing out-of-band interferer. Compared with the traditional heterodyne architecture, the zero reflection network adopted in the architecture can absorb interstage reflection signals, and interference signal amplitude is reduced, so that system linearity is improved. In addition, IF the spurious effects caused by intermodulation products introduced by the RF and LO signals and their harmonics are considered, the output IF signal can be expressed as:
wherein A is LO And omega LO Respectively representing the voltage amplitude and frequency, A, of the LO signal RF (n) and A LO (m) represent the voltage amplitudes of the nth harmonic of the RF signal and the mth harmonic of the LO signal, respectively. This illustrates that the IF input of the heterodyne radiometer is not only subject to RF and LO signalsThe influence of the signs, but also their harmonics. Fig. 11 illustrates the effect of harmonic amplitude on radiometer linearity and it can be seen that the harmonics cause the IP1dB point to transition from the ideal a point to the degraded B point and the system linearity is reduced. Compared with the traditional heterodyne architecture, the zero reflection network adopted in the architecture can effectively absorb the harmonic components at the input end of the mixer, so that the linearity of the system is improved.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (8)
1. A radiometer based on a zero reflection network, comprising: a multi-stage low noise amplifier and a zero reflection network;
the multistage low noise amplifier includes: n cascaded single-stage low-noise amplification units which are sequentially marked as a first-stage low-noise amplification unit, … …, an ith-stage low-noise amplification unit, … … and an Nth-stage low-noise amplification unit are used for amplifying a radio-frequency input signal,
the zero reflection network is used for matching the output impedance of the multistage low noise amplifier and absorbing out-of-band reflection signals to realize no-reflection signals at a port;
the zero reflection network includes: the circuit comprises L-stage matching circuits and resistive elements, wherein the L-stage matching circuits are sequentially connected in series;
the matching circuit is used for transforming the input complex impedance into a parallel impedance value of a port impedance and a resistive element in a pass band and transforming the parallel impedance value to infinity in a stop band;
the resistive element is used for further transforming infinite impedance generated outside the band into a matching state and dissipating absorbed reflected signals, the resistance value of the resistive element is selected near the impedance value of the output port, and the impedance approaching the infinite impedance outside the band is matched to the impedance of the output port through parallel connection, so that the output port has no reflected signals in the full frequency band;
wherein N represents the number of the single-stage low-noise amplification units, i represents the serial number of the single-stage low-noise amplification units, N is an integer greater than or equal to 2, and i is greater than or equal to 1 and less than or equal to N; l represents the number of matching circuits and is a positive integer greater than or equal to 1.
2. The radiometer of claim 1, wherein said zero reflection network is connected to the output of said nth stage low noise amplification unit for matching in-band impedance and absorbing out-of-band reflected signals.
3. The radiometer of claim 1, wherein the zero reflection network is disposed between any two of the N single-stage low noise amplification units.
4. The radiometer of claim 1, wherein the radiometer comprises M zero-reflection networks, each disposed at an output of a respective one of the low-noise amplification units; any zero reflection network can be arranged between the Nth-stage low noise amplification unit or the ith-stage low noise amplification unit and the (i + 1) th-stage low noise amplification unit in common (2) N -1) a species-derived framework; wherein M is more than or equal to 1 and less than or equal to N, and i is more than or equal to 1 and less than or equal to N-1.
5. The radiometer of claim 1, wherein the matching circuit comprises: a matching unit disposed at a previous stage, and an impedance converter disposed at a subsequent stage and multiplexed;
the matching unit is used for realizing complex impedance matching in a passband;
the impedance transformer is multiplexed and generates an out-of-band tending infinite impedance that is transformed to a matched state by the resistive element and dissipates the absorbed reflected signal through the resistive element.
6. The radiometer of claim 5, wherein said impedance transformer is implemented as a series capacitor or series coupled transmission line open at both ends.
7. The radiometer of any of claims 1-6, further comprising a mixer coupled to an output of the zero reflection network for mixing the amplified radio frequency signal and the local oscillator signal and outputting an intermediate frequency signal.
8. The radiometer of any of claims 1-6, further comprising a detector coupled to an output of the zero reflection network for converting the amplified radio frequency signal to a direct current signal and outputting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111005346.7A CN113739931B (en) | 2021-08-30 | 2021-08-30 | Radiometer based on zero reflection network |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111005346.7A CN113739931B (en) | 2021-08-30 | 2021-08-30 | Radiometer based on zero reflection network |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113739931A CN113739931A (en) | 2021-12-03 |
| CN113739931B true CN113739931B (en) | 2022-11-22 |
Family
ID=78733860
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111005346.7A Active CN113739931B (en) | 2021-08-30 | 2021-08-30 | Radiometer based on zero reflection network |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113739931B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140170996A1 (en) * | 2011-07-28 | 2014-06-19 | Lg Innotek Co., Ltd | Impedance Matching Apparatus and Impedance Matching Method |
| CN106505955A (en) * | 2016-10-26 | 2017-03-15 | 天津大学 | A kind of Ku band broadband low-noise amplifiers based on CMOS technology |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006333390A (en) * | 2005-05-30 | 2006-12-07 | Furukawa Electric Co Ltd:The | Low noise amplifier circuit |
| DE102005058875B4 (en) * | 2005-12-09 | 2016-02-25 | Infineon Technologies Ag | matching |
| CN203377868U (en) * | 2013-06-27 | 2014-01-01 | 深圳市创成微电子有限公司 | Low power consumption radio frequency emission circuit device |
| CN103560801A (en) * | 2013-11-11 | 2014-02-05 | 上海航天测控通信研究所 | Satellite-bone low-noise 13-channel V wave band receiver |
| WO2015199895A1 (en) * | 2014-06-25 | 2015-12-30 | Associated Universities, Inc. | Sub-network enhanced reflectionless filter topology |
| CN207074086U (en) * | 2017-01-25 | 2018-03-06 | 成都杰联祺业电子有限责任公司 | Millimeter wave radiometer receiver |
| CN109450484B (en) * | 2018-11-30 | 2020-04-14 | 普联技术有限公司 | Signal reflection eliminating circuit and method |
| CN210609072U (en) * | 2019-10-27 | 2020-05-22 | 陕西亚成微电子股份有限公司 | Impedance matching circuit |
-
2021
- 2021-08-30 CN CN202111005346.7A patent/CN113739931B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140170996A1 (en) * | 2011-07-28 | 2014-06-19 | Lg Innotek Co., Ltd | Impedance Matching Apparatus and Impedance Matching Method |
| CN106505955A (en) * | 2016-10-26 | 2017-03-15 | 天津大学 | A kind of Ku band broadband low-noise amplifiers based on CMOS technology |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113739931A (en) | 2021-12-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114938204A (en) | SC wave band amplitude-phase consistent frequency conversion assembly | |
| CN114204950B (en) | High-performance broadband microwave receiving channel | |
| EP3041135A1 (en) | Active balun and monolithic microwave integrated circuit incorporating the same for ultra-wide band reception | |
| CN113739931B (en) | Radiometer based on zero reflection network | |
| CN210246765U (en) | Detection system suitable for microwave shielding effectiveness | |
| Bi et al. | An Interstage-Reflectionless V-Band Radiometer With Capacitor-Reused Absorptive Matching in 0.13-μm SiGe BiCMOS | |
| CN116995383A (en) | Balanced linear phase band-pass filter with differential mode non-reflection characteristic | |
| CN113726304B (en) | Zero reflection network based on complex impedance matching | |
| CN113381779B (en) | Ultra wideband receiver | |
| US7542735B2 (en) | Multi-octave differential upconverter | |
| CN108490333B (en) | Nonlinear S parameter inspection device | |
| CN114050791A (en) | Multi-octave broadband frequency conversion assembly | |
| CN206099908U (en) | Ku wave band amplifier circuit | |
| Gong et al. | Design of a V-band low noise amplifier for passive millimeter wave imaging application | |
| CN113671264A (en) | Switch type multi-channel radiometer | |
| RU2254590C1 (en) | Radar receiver with large dynamic range by intermodulation of third order | |
| CN115622519A (en) | Band-notch low-noise amplifier based on LC resonance technology and method for improving out-of-band input 1dB compression point thereof | |
| CN111683027A (en) | Satellite up-converter based on intermediate frequency analog predistortion | |
| CN114629513B (en) | Receiving circuit, absorption filter and receiver | |
| CN220067408U (en) | Wideband dynamic multipath parallel receiver | |
| US5689210A (en) | Active distributed signal sampler | |
| CN217563616U (en) | K/Ka down converter | |
| Ginzberg et al. | Transceiver Architectures for Full Duplex Systems with Unmatched Receiver | |
| CN108566218A (en) | A kind of small-sized Direct Conversion wide band radio-frequency reception system | |
| CN210431847U (en) | Frequency conversion assembly for receiving front end |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |