CN102494808B - Microcalorimeter, power reference system utilizing microcalorimeter and measuring method - Google Patents

Abstract

The invention provides a microcalorimeter, a power reference system utilizing the microcalorimeter and a measuring principle thereof. The microcalorimeter has an structure of an auxiliary heater, the power reference system applies current bias to the auxiliary heater of the microcalorimeter by the aid of an auxiliary heating direct-current substitute instrument so as to realize direct-current substitution measurement to a heat insulation section, and effective efficiency of a working end can be acquired by a short-circuiter and calibration tests. Affection on a thermistor mount according to the transfer standards is eliminated during computing, S parameter measurement and side-arm power monitoring are omitted, tracing patch of the radiofrequency power reference is changed, and only voltage reference can be traced. In addition, the power reference system utilizing the measuring principle will be the national radio power reference.

Description

Microcalorimeter, use power reference system and the measuring method of this microcalorimeter

Technical field

The present invention relates to microwave power reference measurement technical field, relate to especially a kind of microcalorimeter, use power reference system and the measuring method thereof of this microcalorimeter.

Background technology

Because the power reference accuracy of measurement based on calorimetric mode is high, therefore as national microwave power benchmark, usually adopt calorimeter or microcalorimeter.Calorimeter is to using microwave pad as microwave power absorption piece, and microcalorimeter is to using thermistor mount as microwave power absorption piece, and the latter has fast response time, transmits convenient, simple to operate feature.The object of microcalorimeter is to measure the effective efficiency of thermistor mount.

In WR22 (33GHz-50GHz) frequency range various countries, all adopt microcalorimeter at present.As shown in Figure 1, be the structural drawing of existing microcalorimeter.Tradition microcalorimeter measuring system mainly consists of following several parts:

1) input waveguide, is input to signal in power seat;

2) benchmark chassis, connects input waveguide and chassis connector;

3) chassis connector, is used for connecting base plate and isolation section;

4) isolation section and engagement flange;

5) operating power seat and reference power seat;

6) enclosing cover, with the water isolation of benchmark chassis sealing with outside;

7) thermoelectric pile, the temperature rise of induction working end, converts electric signal to;

8) peripheral instrument, controls software.

In Fig. 1, thermoelectric pile is for responding to the temperature variation of working end, and reference edge provides the reference point of temperature constant for it, and isolation section is used for carrying out heat insulation.Whole calorimeter assembly is placed in Water Tank with Temp.-controlled hermetically, and four linear heat generation rates are counted power seat bias voltage is provided, and receives volt voltage table for measuring thermoelectric pile voltage.Whole measuring process is roughly: when not adding microwave, in the power seat of working end, electric bridge is biased in a DC voltage by four linear heat generation rate meters, and now power seat bias voltage is v ₁, after system thermal equilibrium, thermoelectric pile reading is e ₁; Add after microwave power, microwave dissipates and produces heat at power seat, therefore electric bridge rebalancing, bias voltage is reduced to v ₂, in system, reach after thermal equilibrium, recording thermoelectric pile reading is e ₂.Suppose that R is power seat biasing resistor, DC substitution power P _bfor:

$P_b=\frac{v_1^2-v_2^2}{R}---\left(1\right)$

Due to the wave guide wall loss of power seat and alternative unequal effect, be dissipated in the microwave power P on power seat _rfcan not by alternative power, be represented completely, so definable effective efficiency is:

${\mathrm{\&eta;}}_e=\frac{P_b}{P_{\mathrm{rf}}}=g\frac{1-v_2^2/{\mathrm{<figure-callout\; id="1"\; label="v"\; filenames="HDA0000110732440000011.png,HDA0000110732440000021.png"\; state="\{\{state\}\}">v</figure-callout>}}_1^2}{e_2/e_1-v_2^2/v_1^2}---\left(2\right)$

Wherein, g is a modifying factor relevant with frequency, and measuring effective efficiency key is to measure g.

At present, the computing method of modifying factor g adopt short-circuiting device method conventionally, on engagement flange reference surface, put into short-circuiting device, because short-circuiting device is made by place a scale copper between engagement flange and power seat, so the thermal characteristics of microcalorimeter does not almost change.But the uncertainty of the measurement of reflection-factor of short-circuiting device is very large on the impact of modifying factor uncertainty.First can measure by network analyzer the reflection coefficient of power seat, short-circuiting device, signal source, i.e. Γ _mfor the reflection coefficient of power seat, Γ _fSfor the reflection coefficient of short-circuiting device, Γ _gEfor signal source reflection coefficient.K ₁for the scale factor of thermoelectric pile output for power stage, because power variation is very little, can think that power is in variation range here, the output of thermoelectric pile is linear, so k ₁this parameter can be calculated by the ratio that does not add the output of thermoelectric pile in radio frequency situation and DC power.Then divide two different modes to measure: the one, under short-circuiting device measurement pattern, recording thermoelectric pile change in voltage is e _fS, the other arm power seat DC substitution power of directional coupler is P _3FS; The 2nd, under mode standard, do not add short-circuiting device, microwave incides the calibration power seat of microcalorimeter inside, and now recording the alternative power of calibration power seat is P _s, the other arm power seat DC substitution power of directional coupler is P _3S, its effective efficiency is η _e.First calculate under mode standard, incide the microwave power P of power seat _iFS:

$P_{\mathrm{IFS}}=\frac{P_S}{{\mathrm{\&eta;}}_e(1-{\left|{\mathrm{\&Gamma;}}_M\right|}^2)}\frac{P_{3\mathrm{FS}}}{P_{3S}}\frac{{|1-{\mathrm{\&Gamma;}}_{\mathrm{GE}}{\mathrm{\&Gamma;}}_M|}^2}{{|1-{\mathrm{\&Gamma;}}_{\mathrm{GE}}{\mathrm{\&Gamma;}}_{\mathrm{FS}}|}^2}---\left(3\right)$

G is:

$g=1+\frac{1+{\left|{\mathrm{\&Gamma;}}_M\right|}^2}{1-{\left|{\mathrm{\&Gamma;}}_M\right|}^2}(\frac{e_{\mathrm{FS}}}{k_1{P}_{\mathrm{IFS}}(1+{\left|{\mathrm{\&Gamma;}}_{\mathrm{FS}}\right|}^2)}-\frac{1-{\left|{\mathrm{\&Gamma;}}_{\mathrm{FS}}\right|}^2}{1+{\left|{\mathrm{\&Gamma;}}_{\mathrm{FS}}\right|}^2})---\left(4\right)$

In (4) formula, η _ebe in hypothesis g=1 situation in fact, by (2) formula, calculated.

As can be seen from the above description, the shortcoming of prior art is because the S parameter of short-circuiting device, directional coupler, power seat need to be measured with network analyzer, uncertainty will be traceable to network parameter like this, and network parameter is closely related with power, will have contradiction like this.And in existing microcalorimeter evaluation process, all need to measure the scattering parameter of short-circuiting device, thermistor mount, dummy source, uncertainty is traceable to network analyzer.

Summary of the invention

The present invention is intended at least solve the technical matters existing in prior art, special power reference system and the measuring method thereof that has proposed a kind of microcalorimeter, used this microcalorimeter of innovating.

In order to realize above-mentioned purpose of the present invention, according to a first aspect of the invention, the invention provides a kind of microcalorimeter, it comprises benchmark chassis and the enclosing cover that is connected described benchmark chassis, and the chamber being formed by described benchmark chassis and the sealing of described enclosing cover; Chassis connector, this chassis connector is arranged in described chamber and is connected with described benchmark chassis; The first isolation section and the second isolation section, described the first isolation section and the second isolation section are connected on described benchmark chassis by chassis connector; Working end and reference edge, described working end is connected on described the first isolation section by the first flange, and described reference edge is connected on described the second isolation section by the second flange; Input waveguide, described input waveguide is connected with described chassis connector, for measured signal being input to described working end; Thermoelectric pile, described thermoelectric pile is connected between described working end and reference edge, the temperature error signal for detection of described working end with respect to described reference edge; Thermistor, described thermistor is formed in described the first isolation section and described the second isolation section, for reflecting the temperature variation of described the first isolation section and described the second isolation section; Bridge for measuring temperature, described bridge for measuring temperature is connected with the thermistor of described the second isolation section, for detection of temperature rise and by temperature rise, converts electric signal to described the first isolation section respectively; And auxiliary heater, described auxiliary heater is formed on described the first flange, is used to described the first isolation section heating.

Microcalorimeter of the present invention adopts auxiliary heater structure, isolation section is carried out to direct current and substitute measurement, in calculating, deducted the impact on Transfer Standards-thermistor mount, without any need for scattering parameter measure, do not need other arm monitoring yet, just obtain effective efficiency, improved the accuracy of microcalorimeter.

In order to realize above-mentioned purpose of the present invention, according to a second aspect of the invention, provide a kind of power reference system of using microcalorimeter of the present invention, it comprises: microcalorimeter; Signal source, the signal output part of described signal source is connected with the signal input part of described microcalorimeter; Power meter, the signal input part of described power meter is connected with the working end of described microcalorimeter, described power meter and DC (Direct Current, direct current) with reference to being connected with power measuring system, the signal output part of described power measuring system is connected with the AM of described signal source (tuning) signal input part, for described signal source provides fixed ampllitude feedback; Auxiliary heating direct current substitutes instrument, and described auxiliary heating direct current substitutes instrument and is connected with auxiliary heater with the thermoelectric pile of described microcalorimeter, for receiving the temperature error signal that described thermoelectric pile records and applying power bias to described auxiliary heater; Voltage table 1, described voltage table 1 is connected with described power meter, for monitoring the voltage of described power meter; Voltage table 2, described voltage table 2 substitutes instrument with described auxiliary heating direct current and is connected, and substitutes the voltage of instrument for monitoring described auxiliary heating direct current; Voltage table 3, described voltage table 3 is connected with described bridge for measuring temperature, by the temperature rise of described the first isolation section of described voltage table 3 monitoring.

Power reference system of the present invention, by auxiliary heating direct current, substitute instrument and apply power bias to the auxiliary heater of microcalorimeter, isolation section is carried out to direct current and substitute measurement, only need to pass through short-circuiting device, calibration experiments, just can draw the effective efficiency of working end, and not needing S parameter measurement and other arm power monitoring, this new power reference system will become China national wireless power benchmark.

In order to realize above-mentioned purpose of the present invention, according to a third aspect of the present invention, provide a kind of power measurement method of power reference system of the present invention, it comprises the steps:

S1: sandwich short-circuit piece between working end and the first flange, working end bias voltage V when measuring-signal source is closed after system balancing _{dC, sh, off}, bridge for measuring temperature initial voltage e _{i, sh, 0}, auxiliary heater bias voltage V _{a, sh, off}, working end bias voltage V when open in measuring-signal source after system balancing _{dC, sh, on}, bridge for measuring temperature initial voltage e _{i, sh, on}, auxiliary heater bias voltage V _{a, sh, on};

S2: remove the short-circuit piece between working end and the first flange, working end bias voltage V when measuring-signal source is closed after system balancing _{dC, cal, off}, bridge for measuring temperature initial voltage e _{i, cal, 0}, auxiliary heater bias voltage V _{a, cal, off}, working end bias voltage V when open in measuring-signal source after system balancing _{dC, cal, on}, bridge for measuring temperature initial voltage e _{i, cal, on}, auxiliary heater bias voltage V _{a, cal, on};

S3: calculate the power P that makes working end temperature increase _dw,

$k_w{P}_{\mathrm{dw}}=P_{A,\mathrm{sub},\mathrm{cal}}-\frac{{\mathrm{\&Delta;e}}_{i,\mathrm{cal}}}{{\mathrm{\&Delta;e}}_{i,\mathrm{sh}}}{P}_{A,\mathrm{sub},\mathrm{sh}}+\frac{{\mathrm{\&Delta;e}}_{i,\mathrm{cal}}}{{\mathrm{\&Delta;e}}_{i,\mathrm{sh}}}{k}_{\mathrm{sh}}{P}_{\mathrm{sh}},$

Wherein, k _wfor working end absorption signal power causes the coefficient of the variation of auxiliary heater balanced power,

K _shfor isolation section and flange absorption signal power cause the coefficient of the variation of auxiliary heater balanced power,

P _shfor the signal power of isolation section and flange absorption,

$P_{A,\mathrm{sub},\mathrm{cal}}=\frac{{V_{A,\mathrm{cal},\mathrm{off}}}^2-{V_{A,\mathrm{cal},\mathrm{on}}}^2}{R_A},$

$P_{A,\mathrm{sub},\mathrm{sh}}=\frac{{V_{A,\mathrm{sh},\mathrm{off}}}^2-{V_{A,\mathrm{sh},\mathrm{on}}}^2}{R_A},$

Δe _i，sh＝e _i，sh，on-e _i，sh，0，

Δe _i，cal＝e _i，cal，on-e _i，cal，0，

S4: the effective efficiency η of evaluation work end _e,

${\mathrm{\&eta;}}_e=\frac{P_{\mathrm{sub}}}{P_{\mathrm{sub}}+P_{\mathrm{dw}}}=\frac{P_{\mathrm{sub}}}{P_{\mathrm{sub}}+\frac{1}{k_w}(P_{A,\mathrm{sub},\mathrm{cal}}-\frac{{\mathrm{\&Delta;e}}_{i,\mathrm{cal}}}{{\mathrm{\&Delta;e}}_{i,\mathrm{sh}}}{P}_{A,\mathrm{sub},\mathrm{sh}}+\frac{{\mathrm{\&Delta;e}}_{i,\mathrm{cal}}}{{\mathrm{\&Delta;e}}_{i,\mathrm{sh}}}{k}_{\mathrm{sh}}{P}_{\mathrm{sh}})}.$

The measuring principle of power reference system in the present invention, does not need to measure the scattering parameter of short-circuiting device, thermistor mount, dummy source, just can obtain effective efficiency.This new measuring principle is based on the direct current of isolation section is substituted and measured, thereby in calculating, has deducted the impact on Transfer Standards-thermistor mount.This new method has changed the path of tracing to the source of radio-frequency power benchmark, makes it be traceable to voltage reference, utilizes the power reference system of this measuring principle will become China national wireless power benchmark.

Additional aspect of the present invention and advantage in the following description part provide, and part will become obviously from the following description, or recognize by practice of the present invention.

Accompanying drawing explanation

Above-mentioned and/or additional aspect of the present invention and advantage accompanying drawing below combination obviously and is easily understood becoming the description of embodiment, wherein:

Fig. 1 is the structural representation of existing microcalorimeter;

Fig. 2 is the structural representation of the microcalorimeter of the embodiment of the present invention;

Fig. 3 is the product structure figure of microcalorimeter shown in Fig. 2; With

Fig. 4 is the power reference system connection diagram of the embodiment of the present invention.

Embodiment

Describe embodiments of the invention below in detail, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has the element of identical or similar functions from start to finish.Below by the embodiment being described with reference to the drawings, be exemplary, only for explaining the present invention, and can not be interpreted as limitation of the present invention.

In description of the invention, it will be appreciated that, term " longitudinally ", " laterally ", " on ", orientation or the position relationship of the indication such as D score, 'fornt', 'back', " left side ", " right side ", " vertically ", " level ", " top ", " end " " interior ", " outward " be based on orientation shown in the drawings or position relationship, only the present invention for convenience of description and simplified characterization, rather than indicate or imply that the device of indication or element must have specific orientation, with specific orientation, construct and operation, therefore can not be interpreted as limitation of the present invention.

In description of the invention, unless otherwise prescribed and limit, it should be noted that, term " installation ", " being connected ", " connection " should be interpreted broadly, for example, can be mechanical connection or electrical connection, also can be the connection of two element internals, can be to be directly connected, and also can indirectly be connected by intermediary, for the ordinary skill in the art, can understand as the case may be the concrete meaning of above-mentioned term.

Fig. 2 shows the structural representation of microcalorimeter according to a preferred embodiment of the present invention, Fig. 3 is the product structure figure of microcalorimeter shown in Fig. 2, as seen from the figure, this microcalorimeter comprises enclosing cover, benchmark chassis, chassis connector, the first isolation section, the second isolation section, working end, reference edge, the first flange, the second flange, thermistor, input waveguide, bridge for measuring temperature and auxiliary heater, wherein, benchmark chassis is connected with enclosing cover, this benchmark chassis and enclosing cover sealing form Yi Ge airtight chamber, so that each element in microcalorimeter is in identical temperature environment, guaranteed the accuracy of measuring, in Gai airtight chamber, be provided with the chassis connector being connected with benchmark chassis, the first isolation section and the second isolation section are connected on benchmark chassis by chassis connector, working end is connected on the first isolation section by the first flange, and reference edge is connected on the second isolation section by the second flange, input waveguide is connected with chassis connector, for measured signal is input to working end, thermoelectric pile is connected between working end and reference edge, the temperature error signal for detection of working end with respect to reference edge, thermistor is formed in the first isolation section and the second isolation section, for reflecting the temperature variation of the first isolation section and described the second isolation section, bridge for measuring temperature is connected with the thermistor of the second isolation section with the first isolation section respectively, for detection of the first isolation section with respect to the temperature rise of the second isolation section and convert temperature rise to electric signal, auxiliary heater is formed on first on flange, is used to the first isolation section heating.

A kind of embodiment of auxiliary heater structure has been shown in Fig. 2 and Fig. 3, and certainly, this is only example, and object does not lie in restriction the present invention, and its effect is to make the first isolation section produce temperature rise, can be but be not limited to the structure shown in Fig. 2.In the present embodiment, it is the first isolation section heating that microcalorimeter adopts auxiliary heater, and this auxiliary heater can be but be not limited to make the first isolation section to produce one of film thermal resistance sheet, ceramic resistor sheet, ring-shaped resistor sheet of temperature rise.

Fig. 4 shows the power reference system of employing microcalorimeter of the present invention according to a preferred embodiment of the present invention, it comprises that microcalorimeter, signal source, power meter, DC reference, power measuring system, auxiliary heating direct current substitute instrument, voltage table 1, voltage table 2, voltage 3, wherein, the signal output part of signal source and the signal input part of microcalorimeter are connected; The signal input part of power meter is connected with the working end of microcalorimeter, reference is connected with power measuring system power meter with DC, the signal output part of power measuring system is connected with the AM signal input part of signal source, for providing, signal source warmly takes feedback, in the present embodiment, signal source is RF (Radio Frequency, radio frequency) signal source; Auxiliary heating direct current substitutes instrument and is connected with auxiliary heater with the thermoelectric pile of microcalorimeter, for receiving the temperature error signal that thermoelectric pile records and applying power bias to auxiliary heater; Voltage table 1 is connected with power meter, for monitoring the voltage of described power meter; Voltage table 2 substitutes instrument with auxiliary heating direct current and is connected, and substitutes the voltage of instrument for monitoring auxiliary heating direct current; Voltage table 3 is connected with bridge for measuring temperature, by the temperature rise of voltage table 3 monitoring the first isolation section.In the present embodiment, the power bias that the alternative instrument of auxiliary heating direct current applies to auxiliary heater is 1.0 milliwatts.Power reference system of the present invention, substitutes by auxiliary heating direct current the current offset that instrument applies to the auxiliary heater of microcalorimeter, by the direct current of isolation section is substituted and measured, has deducted the impact on Transfer Standards-thermistor mount in calculating.This new power reference system has changed the path of tracing to the source of radio-frequency power benchmark, makes it be traceable to voltage reference, will become China national wireless power benchmark.

The above-mentioned power reference system that embodiment proposes for a more clear understanding of the present invention, the invention allows for the embodiment of the measuring principle of above-mentioned power reference system, and the amount principle of this power reference system comprises the steps:

S1: short-circuiting device is measured, and assembles microcalorimeter according to Fig. 2, sandwiches short-circuit piece between working end and the first flange, and radiofrequency signal is all reflected in porch, working end.According to Fig. 3, connect power reference system, close radio-frequency signal source, make whole microcalorimeter thermal equilibrium.Writing task end bias voltage V _{dC, sh, off}, bridge for measuring temperature initial voltage e _{i, sh, 0}, auxiliary heating direct current substitutes instrument bias voltage V _{a, sh, off}; Open radio frequency, after system rebalancing, writing task end bias voltage V _{dC, sh, on}, bridge for measuring temperature initial voltage e _{i, sh, on}, auxiliary heating direct current substitutes instrument bias voltage V _{a, sh, on}.

S2: calibration measurement, according to Fig. 2, assemble microcalorimeter, between working end and the first flange, do not place short-circuit piece.According to Fig. 3, connect power reference system, close radio-frequency signal source, make whole microcalorimeter thermal equilibrium, writing task end bias voltage V _{dC, cal, off}, bridge for measuring temperature initial voltage e _{i, cal, 0}, auxiliary heating direct current substitutes instrument bias voltage V _{a, cal, off}; Open radio frequency, after system rebalancing, writing task end bias voltage V _{dC, cal, on}, bridge for measuring temperature initial voltage e _{i, cal, on}, auxiliary heating direct current substitutes instrument bias voltage V _{a, cal, on}.

S3: calculate the power P that makes working end temperature increase _dw,

The effective efficiency η of the working end of microcalorimeter _efor DC substitution power P _subabsorb net power P with working end _rfratio, that is:

${\mathrm{\&eta;}}_e=\frac{P_{\mathrm{sub}}}{P_{\mathrm{rf}}}---\left(5\right)$

Be that working end has absorbed radio-frequency power, a part has been substituted by direct current, and another part has caused the temperature rise of the working end after DC balance.Like this can be P _rfbe divided into two parts, a part has been substituted P by direct current _sub, another part has caused the temperature rise of working end, and this Partial Power is P _dw, that is:

${\mathrm{\&eta;}}_e=\frac{P_{\mathrm{sub}}}{P_{\mathrm{sub}}+P_{\mathrm{dw}}}---\left(6\right)$

P _subcan be recorded by electric current self-balancing bridge (four linear heat generation rate meters), the DC power of establishing working end while not adding radio-frequency power is P _{dC, off}, adding the DC power of working end after radio-frequency power is P _{dC, on}:

$P_{\mathrm{sub}}=P_{\mathrm{DC},\mathrm{off}}-P_{\mathrm{DC},\mathrm{on}}=\frac{{V_{\mathrm{DC},\mathrm{cal},\mathrm{off}}}^2-{V_{\mathrm{DC},\mathrm{cal},\mathrm{on}}}^2}{R}---\left(7\right)$

In order to measure P _dw, on isolation section, having added auxiliary DC heating structure, auxiliary heating direct current substitutes instrument and to auxiliary DC heating structure, applies the direct current biasing of 1mW.After adding radio-frequency power, isolation section, flange and working end all can produce because having absorbed radio-frequency power temperature rise, between the radio-frequency power that the radio-frequency power that flange absorbs and isolation section absorb, have definite relation, and its one is considered, are designated as P _{i & f}, they all have contribution to seat wall temperature liter.Therefore,, when considering that isolation section and flange affect, auxiliary heating substitutes power P _{a, sub}can be written as:

P _A，sub＝P _A，off-P _A，on＝k _wP _dw+k _i&fP _i&f (8)

Wherein,

P _{i & f}: the radio-frequency power that isolation section and flange absorb;

K _{i & f}: isolation section and flange absorb the coefficient that radio-frequency power causes the variation of auxiliary heater balanced power;

K _w: working end absorbs the coefficient that radio-frequency power causes the variation of auxiliary heater balanced power.

In short-circuiting device measuring process, bridge for measuring temperature output voltage changes delta e _{i, sh}and auxiliary heater DC power changes P _{a, sub, sh}for:

Δe _i，sh＝e _i，sh，on-e _i，sh，0 (9)

Δe _i，sh＝k _i&f，tP _i&f，sh (10)

$P_{A,\mathrm{sub},\mathrm{sh}}=\frac{{V_{A,\mathrm{sh},\mathrm{off}}}^2-{V_{A,\mathrm{sh},\mathrm{on}}}^2}{R_A}---\left(11\right)$

P _A，sub，sh＝k _i&fP _i&f，sh+k _shP _sh (12)

K _{i & f, t}: isolation section and flange absorb the factor of influence of radio-frequency power to bridge for measuring temperature output voltage.

P _{i, sh1}: isolation section bridge for measuring temperature output voltage variable quantity is Δ e _{i, sh1}time the isolation section radio-frequency power that absorbs;

By formula (10) and (12), can be drawn:

In calibration measurement process, isolation section bridge for measuring temperature output voltage changes delta e _{i, cal}for:

Δe _i，cal＝k _i&f，tP _i&f，cal； (14)

Δe _i，cal＝e _i，cal，on-e _i，cal，0 (15)

Auxiliary heater DC power changes P _{a, sub, cal}comprise three parts: the power of isolation section and flange changes P _{i & f, cal}, make working end produce the power P of temperature rise _dw, have:

P _{A，sub，cal}＝k _i&fP _i&f，cal+k _wP _dw； (16)

$P_{A,\mathrm{sub},\mathrm{cal}}=\frac{{V_{A,\mathrm{cal},\mathrm{off}}}^2-{V_{A,\mathrm{cal},\mathrm{on}}}^2}{R_A}---\left(17\right)$

By formula (14) and (16), can be drawn:

By formula (13), compare and can draw with (18):

$\frac{{\mathrm{\&Delta;e}}_{i,\mathrm{sh}}}{{\mathrm{\&Delta;e}}_{i,\mathrm{cal}}}=\frac{P_{A,\mathrm{sub},\mathrm{sh}}-k_{\mathrm{sh}}{P}_{\mathrm{sh}}}{P_{A,\mathrm{sub},\mathrm{cal}}-k_w{P}_{\mathrm{dw}}}---\left(19\right)$

By formula (19), solved:

$k_w{P}_{\mathrm{dw}}=P_{A,\mathrm{sub},\mathrm{cal}}-\frac{{\mathrm{\&Delta;e}}_{i,\mathrm{cal}}}{{\mathrm{\&Delta;e}}_{i,\mathrm{sh}}}{P}_{A,\mathrm{sub},\mathrm{sh}}+\frac{{\mathrm{\&Delta;e}}_{i,\mathrm{cal}}}{{\mathrm{\&Delta;e}}_{i,\mathrm{sh}}}{k}_{\mathrm{sh}}{P}_{\mathrm{sh}},k_w\&ap;1---\left(20\right)$

S4: the effective efficiency η of evaluation work end _e,

${\mathrm{\&eta;}}_e=\frac{P_{\mathrm{sub}}}{P_{\mathrm{sub}}+P_{\mathrm{dw}}}=\frac{P_{\mathrm{sub}}}{P_{\mathrm{sub}}+\frac{1}{k_w}(P_{A,\mathrm{sub},\mathrm{cal}}-\frac{{\mathrm{\&Delta;e}}_{i,\mathrm{cal}}}{{\mathrm{\&Delta;e}}_{i,\mathrm{sh}}}{P}_{A,\mathrm{sub},\mathrm{sh}}+\frac{{\mathrm{\&Delta;e}}_{i,\mathrm{cal}}}{{\mathrm{\&Delta;e}}_{i,\mathrm{sh}}}{k}_{\mathrm{sh}}{P}_{\mathrm{sh}})}---\left(21\right)$

In the present embodiment, absorption signal power in working end causes the coefficient k of the variation of auxiliary heater balanced power _waccording to the method that changes working end balanced power, test definite, in a kind of embodiment being more preferably, k _wvalue be 1.0.

In the present embodiment, the radio-frequency power dissipating on short-circuit piece is 0.05% of the radio-frequency power that dissipates on isolation section, flange and thermistor mount.

Value based in above embodiment, formula (20) and formula (21) can be write as:

$k_w{P}_{\mathrm{dw}}\&ap;P_{A,\mathrm{sub},\mathrm{cal}}-\frac{{\mathrm{\&Delta;e}}_{i,\mathrm{cal}}}{{\mathrm{\&Delta;e}}_{i,\mathrm{sh}}}{P}_{A,\mathrm{sub},\mathrm{sh}},k_w\&ap;1---\left(22\right)$

${\mathrm{\&eta;}}_e\&ap;\frac{P_{\mathrm{sub}}}{P_{\mathrm{sub}}+\frac{1}{k_w}(P_{A,\mathrm{sub},\mathrm{cal}}-\frac{{\mathrm{\&Delta;e}}_{i,\mathrm{cal}}}{{\mathrm{\&Delta;e}}_{i,\mathrm{sh}}}{P}_{A,\mathrm{sub},\mathrm{sh}})}---\left(23\right)$

By above-mentioned theory, calculate, as long as by short-circuiting device, calibration experiments, just can draw the effective efficiency of thermistor mount, and not need S parameter measurement and other arm power monitoring.This new method has changed the path of tracing to the source of radio-frequency power benchmark, makes it be traceable to voltage reference, utilizes the power reference system of this measuring principle will become China national wireless power benchmark.

In the description of this instructions, the description of reference term " embodiment ", " some embodiment ", " example ", " concrete example " or " some examples " etc. means to be contained at least one embodiment of the present invention or example in conjunction with specific features, structure, material or the feature of this embodiment or example description.In this manual, the schematic statement of above-mentioned term is not necessarily referred to identical embodiment or example.And the specific features of description, structure, material or feature can be with suitable mode combinations in any one or more embodiment or example.

Although illustrated and described embodiments of the invention, those having ordinary skill in the art will appreciate that: in the situation that not departing from principle of the present invention and aim, can carry out multiple variation, modification, replacement and modification to these embodiment, scope of the present invention is limited by claim and equivalent thereof.

Claims (4)

1. a microcalorimeter, is characterized in that, comprising:

Benchmark chassis and the enclosing cover that is connected described benchmark chassis, and the chamber being formed by described benchmark chassis and the sealing of described enclosing cover;

Chassis connector, described chassis connector is arranged in described chamber and is connected with described benchmark chassis;

The first isolation section and the second isolation section, described the first isolation section and the second isolation section are connected on described benchmark chassis by chassis connector;

Working end and reference edge, described working end is connected on described the first isolation section by the first flange, and described reference edge is connected on described the second isolation section by the second flange;

Input waveguide, described input waveguide is connected with described chassis connector, for measured signal being input to described working end;

Thermoelectric pile, described thermoelectric pile is connected between described working end and reference edge, the temperature error signal for detection of described working end with respect to described reference edge;

Thermistor, described thermistor is respectively formed in described the first isolation section and described the second isolation section, for reflecting the temperature variation of described the first isolation section and described the second isolation section;

Bridge for measuring temperature, described bridge for measuring temperature is connected with the thermistor of described the second isolation section, for detection of temperature rise and by temperature rise, converts electric signal to described the first isolation section respectively; Auxiliary heater, described auxiliary heater is formed on described the first flange, is used to described the first isolation section heating.

2. microcalorimeter as claimed in claim 1, is characterized in that, described auxiliary heater is one of film thermal resistance sheet, ceramic resistor sheet, ring-shaped resistor sheet.

3. a power reference system for microcalorimeter, is characterized in that, comprising:

Microcalorimeter, described microcalorimeter is the microcalorimeter described in claim 1-2 any one;

Signal source, the signal output part of described signal source is connected with the working end of described microcalorimeter;

Power meter, the signal input part of described power meter is connected with the working end of described microcalorimeter, described power meter is connected with power measuring system, described power measuring system is connected with direct current reference, the signal output part of described power measuring system is connected with the amplitude-modulated signal input end of described signal source, for described signal source provides fixed ampllitude feedback;

Auxiliary heating direct current substitutes instrument, and described auxiliary heating direct current substitutes instrument and is connected with auxiliary heater with the thermoelectric pile of described microcalorimeter, for receiving the temperature error signal that described thermoelectric pile records and applying power bias to described auxiliary heater; Voltage table 1, described voltage table 1 is connected with described power meter, for monitoring the voltage of described power meter;

Voltage table 2, described voltage table 2 substitutes instrument with described auxiliary heating direct current and is connected, and substitutes the voltage of instrument for monitoring described auxiliary heating direct current;

Voltage table 3, described voltage table 3 is connected with described bridge for measuring temperature, by the temperature rise of described the first isolation section of described voltage table 3 monitoring.

4. the power reference system of microcalorimeter as claimed in claim 3, is characterized in that, the power bias that the alternative instrument of described auxiliary heating direct current applies to described auxiliary heater is 1.0 milliwatts.

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