JP2009180737A - Millimeter wave transmitting/receiving module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a millimeter-wave transmitting/receiving module having a function for detecting abnormalities or faults. <P>SOLUTION: The millimeter-wave transmitting/receiving module is provided with: a high-frequency circuit connected with a transmitting/receiving antenna of a millimeter-wave transmitting/receiving radar; a signal processing circuit, which makes the high-frequency circuit generate transmission waves and processes a received signal input from the high-frequency circuit; a current monitor for detecting a drain current flowing through the high-frequency circuit; and an ambient temperature monitor for detecting the ambient temperature of the high-frequency circuit. The module is also provided with a transmitted electric power monitoring means which calculates a transmitted electric power value from the electric current value detected by the current monitor in operation, and determines at least whether the calculated transmitted electric power value is in a range of from a prescribed upper limit to a prescribed lower limit at the temperature detected by the ambient temperature monitor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a millimeter wave transmission / reception module used in an apparatus for transmitting and receiving millimeter wave radio waves.

  The millimeter wave is a radio wave having a wavelength of 1 mm to 10 mm, that is, a frequency of 30 GHz to 300 GHz. With the development of semiconductor technology, the cost of millimeter-wave devices has been reduced, and commercialization has become possible. Therefore, the practical application of millimeter-wave has been promoted in various fields such as communication, broadcasting, and sensing. For example, in the field of sensing, radar devices can maintain stable sensing performance regardless of the day and night, and in systems that support safe driving of vehicles, millimeter-wave radar is practically used as a sensor for detecting vehicles and obstacles. (For example, Patent Document 1).

JP 2000-105276 A

  By the way, in the millimeter wave transmission / reception module used in a device that transmits and receives millimeter wave radio waves, if the module is equipped with a function for detecting an abnormality or failure, the load on the host processing system can be reduced, and various abnormalities and failures can be achieved. However, there is a problem that the circuit scale is increased and the problem of downsizing is adversely affected.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a millimeter-wave transceiver module equipped with a function of detecting an abnormality or failure in the millimeter-wave transceiver module while reducing the size.

  In order to solve the above-described problems and achieve the object, the present invention provides a high-frequency circuit connected to a transmission / reception antenna of a radar that transmits and receives millimeter-wave radio waves, generates a transmission radio wave in the high-frequency circuit, and In a millimeter wave transmission / reception module comprising a signal processing circuit for processing a received signal input from, a current monitor for detecting a drain current flowing through the high frequency circuit, and an ambient temperature monitor for detecting an ambient temperature of the high frequency circuit, during operation, A transmission power value is obtained from the detected current value of the current monitor, and at least it is determined whether or not the obtained transmission power value is within a range between a predetermined upper limit value and a lower limit value at the detected temperature of the ambient temperature monitor. A transmission power monitoring means is provided.

  According to the present invention, during operation, a transmission power value can be obtained from the detected current value of the current monitor, a transmission power abnormality can be detected based on the transmission power value, and the monitoring burden on the host processing system can be reduced. There is an effect that can be.

It is a block diagram which shows the structure of the millimeter wave transmission / reception module which is one embodiment of this invention. It is a block diagram which shows the structural example of the bias adjustment system and abnormality monitoring system in the millimeter wave transmission / reception module shown in FIG. FIG. 3 is a diagram for explaining a case where gate voltage setting by the bias adjustment system shown in FIG. It is a flowchart explaining the monitoring operation | movement of transmission power. It is a figure explaining the content of the process sequence which calculates | requires the electric current type | mold threshold value of the fall and increase of the transmission power shown in FIG. It is a figure explaining the content of the judgment procedure of whether it is normal shown in FIG. It is a characteristic view which shows the relationship between drain current and ambient temperature. It is a flowchart explaining the monitoring operation | movement of drain current. It is a characteristic view which shows the relationship between drain voltage and ambient temperature. It is a flowchart explaining the monitoring operation | movement of a drain voltage. It is a flowchart explaining the monitoring operation | movement of the ambient temperature of MMIC. It is a figure explaining the procedure process which investigates whether the junction temperature of MMIC shown in FIG. 11 exceeds the maximum value.

  Exemplary embodiments of a millimeter-wave transceiver module according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a millimeter wave transceiver module according to an embodiment of the present invention. Here, an application example to an FMCW (Frequency Modulated Continuous Wave) millimeter wave radar will be described.

  The millimeter wave transmission / reception module shown in FIG. 1 includes a high-frequency circuit 3 to which a transmission antenna 1 and a reception antenna 2 included in an FMCW radar are connected, and a dedicated integrated circuit (ASIC) 4 connected to the high-frequency circuit 3. . In the ASIC 4, a signal processing circuit 5 and a bias circuit 6 are integrated into an integrated circuit.

  The high-frequency circuit 3 has a voltage control oscillator (hereinafter referred to as “VCO”) 31 that receives a transmission command (triangular wave voltage signal) from the signal processing circuit 4 and generates an FMCW signal, and a VCO 31 as an essential basic element. A directional coupler 32 that provides a part of the FMCW signal to the transmission antenna 1 and the rest as a local signal to the mixer 33, a mixer 33 that converts the frequency of the reception signal of the reception antenna 2 by the local signal, and conversion of the mixer 33 And a video amplifier 34 that amplifies the output and supplies the amplified signal to the signal processing circuit 4 as a received signal.

  The signal processing circuit 5 converts a transmission command (triangular wave voltage signal) from the main circuit unit (hereinafter referred to as “microcomputer”) 51 that performs transmission processing and measurement processing in the FMCW radar into an analog signal, and converts it into an analog signal. 3, a D / A converter 52 to be supplied to the VCO 31, and an A / D converter 53 to convert the received signal from the video amplifier 34 of the high frequency circuit 3 into a digital signal and to supply the digital signal to the microcomputer 51.

  First, in order to facilitate understanding of the present invention, the measurement operation of the FMCW radar will be outlined. The measurement processing system of the FMCW radar basically includes a high-frequency circuit 3 and a signal processing circuit 5 to which the transmission antenna 1 and the reception antenna 2 are connected.

  That is, the VCO 31 receives the triangular wave voltage signal from the signal processing circuit 5 and generates an FMCW signal composed of an ascending modulation signal whose frequency rises with time within a certain period and a descending modulation signal whose frequency falls with time within a certain period. A part of the FMCW signal is supplied from the directional coupler 32 to the transmission antenna 1, and a millimeter wave radio wave is irradiated from the transmission antenna 1 toward the target. The remaining FMCW signal is supplied to the mixer 33 as a local signal. The FMCW signal is, for example, a 70 GHz band millimeter wave signal.

  The reflected wave at the target captured by the receiving antenna 2 is input to the mixer 33 as a received signal. The mixer 33 mixes the received signal from the receiving antenna 2 and the local signal from the directional coupler 32, and outputs a beat signal having a frequency difference between the two. The beat signal is appropriately amplified to a level by the video amplifier 34 and input to the microcomputer 51 via the A / D converter 53. The microcomputer 51 obtains the distance to the target object and the moving speed of the target object from the frequency in the rising modulation period and the frequency in the falling modulation period in the input beat signal.

  In the high-frequency circuit 3, the transmission system (such as the directional coupler 32) and the reception system (such as the mixer 33 and the video amplifier 34) are each configured by a plurality of MMICs. Further, the VCO 31 uses a plurality of MMICs to generate a millimeter wave signal in a 70 GHz band by multiplying, for example, from 19 GHz in multiple stages. Each gate voltage of a large number of MMICs constituting the high-frequency circuit 3 requires bias adjustment in accordance with variations of individual MMICs. Also, the drain voltage requires temperature compensation. In particular, the temperature compensation of the drain voltage for a plurality of MMICs constituting the VCO 31 is important for obtaining a constant transmission power without being affected by the ambient temperature in the actual operation process. Further, it is necessary to be able to confirm the normality of a large number of MMICs constituting the high-frequency circuit 3 in the actual operation process. In this embodiment, such a bias voltage adjustment system and an abnormality monitoring system are configured as follows including the microcomputer 51.

  That is, in the immediate vicinity of the high frequency circuit 3, there are a current monitor 35 for detecting the drain current flowing through the MMIC, an ambient temperature monitor 36 for detecting the ambient temperature of the high frequency circuit 3, and a device for monitoring the upper limit temperature of the junction of the MMIC. A temperature monitor 37 (hereinafter referred to as “DVC”) is provided. The current monitor 35 is configured as shown in FIG. 2, for example, and the detection output is input to the microcomputer 51 via the bias circuit 6. The ambient temperature monitor 36 is composed of, for example, a voltage dividing circuit in which a thermistor and a resistance element are combined. The detected temperature value is converted into a voltage signal and output. The detected output is similarly sent to the microcomputer 51 via the bias circuit 6. Is input. The DVC temperature monitor 37 is arranged in the immediate vicinity of each MMIC, and its detection output is similarly input to the microcomputer 51 via the bias circuit 6.

  In addition to the functions for performing the transmission processing and measurement processing in the FMCW radar described above, the microcomputer 51 includes the outputs of the ambient temperature monitor 36 and the current monitor 35 that are input via the bias circuit 6. A function of adjusting and setting the bias voltage and supplying it to each MMIC from the bias circuit 6, and each of the current monitor 35, the ambient temperature monitor 36, and the DVC temperature monitor 37 input via the bias circuit 6 in the actual operation process. An abnormality monitoring function (see FIG. 2) for confirming the normality and transmission power of many MMICs constituting the high-frequency circuit 3 based on the output is added. Therefore, in this embodiment, the bias circuit 6 is configured to have a so-called interface function between the MMIC of the high-frequency circuit 3 and the microcomputer 51, as shown in FIG.

  The configuration and operation of the bias adjustment system and the abnormality monitoring system according to this embodiment will be described below with reference to FIGS. First, the configuration will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration example of a bias adjustment system and an abnormality monitoring system in the millimeter wave transmission / reception module shown in FIG. Here, the adjustment of the bias voltage is performed in three systems, that is, a transmission MMIC group, a reception MMIC group, and a frequency multiplication MMIC group in the VCO 31. A bias adjustment system shown in FIG. 2 is provided for each of the three MMIC groups. Also, abnormality monitoring in the operation process is performed for each of the three MMIC groups. This is performed in the microcomputer 51 using the bias adjustment system shown in FIG.

  In FIG. 2, the microcomputer 51 is instructed by the control processing unit 54, the control processing unit 54 that performs the calculation and the like by fetching the output value of each monitor during the drain voltage setting process, the gate voltage bias adjustment setting process, and the abnormality monitoring. A drain setting voltage output unit 55 that outputs a drain voltage, a temperature data table that is referred to when the control processing unit 54 performs a drain voltage setting process, and a data area for performing bias adjustment of the gate voltage and monitoring of transmission power A memory 56 provided for storing various data necessary for monitoring abnormality, a gate setting voltage output unit 57 for outputting a gate voltage instructed by the control processing unit 54, and an abnormality based on the processing result of the control processing unit 54 An abnormality determination processing unit 58 that performs determination, and an abnormality result output unit 59 that notifies an abnormality determination result of the abnormality determination processing unit 58 to the outside or a higher processing system. Eteiru. The abnormality determination processing unit 58 uses the memory 56 via the control processing unit 54.

  The bias circuit 6 includes a drain bias regulator 61 including a D / A converter in an input stage, A / D converters 62, 63, and 64, and D / A converters 65-1 to 65-n. Yes. The high-frequency circuit 3 includes MMICs 40-1 to 40-n that are one of the three MMIC groups described above. An ambient temperature monitor 36 and a DVC monitor 37 are provided in the immediate vicinity of the high-frequency circuit 3. The current monitor 35 includes a shunt resistor element 38 and a voltage comparison circuit 39. The resistance value of the shunt resistance element 38 is known, but the value is small.

  The output of the drain setting voltage output unit 55 is given to the drain bias regulator 61. The output of the drain bias regulator 61 is given in common to the drain electrodes D of the MMICs 40-1 to 40-n via the shunt resistor element 38. The voltage across the shunt resistor element 38 is input to the voltage comparison circuit 39, and the output of the voltage comparison circuit 39 is input to the control processing unit 54 via the A / D converter 62. The output of the ambient temperature monitor 36 is input to the control processing unit 54 via the A / D converter 63. The output of the DVC temperature monitor 37 is input to the control processing unit 54 via the A / D converter 64. The D / A converters 65-1 to 65-n are connected in parallel to the output terminal of the gate setting voltage output unit 57. The outputs of the D / A converters 65-1 to 65-n are connected to the MMIC 40-. It is applied to the corresponding gate electrodes G of 1 to 40-n.

  The operation of the bias adjustment system will be described. First, the setting of the drain voltage will be described with reference to FIG. As shown in FIG. 2, the drain voltage is commonly set to the same value for the same MMIC group. However, since it is necessary to consider the ambient temperature in the high-frequency circuit 3, the drain voltage setting process is performed even after the product is shipped. Performed regularly. For this reason, the memory 56 stores in advance a temperature data table indicating the relationship between the temperature value and the set voltage value corresponding to the temperature value.

In FIG. 2, the ambient temperature value detected by the ambient temperature monitor 36 is input to the control processing unit 54 via the A / D converter 63. The control processing unit 54 periodically samples the output value of the A / D converter 63 to obtain the ambient temperature value. Since the ambient temperature value detected by the ambient temperature monitor 36 is a voltage value as described above, the control processing unit 54 applies the output value (voltage value) of the A / D converter 63 to the voltage dividing circuit. The thermist resistance value R is obtained from the voltage, and the ambient temperature value T is obtained using the following equation (1).
R = R ₀ × exp {B × [(1 / T) − (1 / T ₀ )]} (1)
In Equation (1), R ₀ is a known resistance value at room temperature (25 degrees), B is a temperature parameter, and T ₀ is room temperature (25 degrees).

  When obtaining the ambient temperature value, the control processing unit 54 reads the set voltage value corresponding to the ambient temperature value from the memory 56 and supplies it to the drain set voltage output unit 55. Accordingly, the set voltage data is output from the drain set voltage output unit 55 to the drain bias regulator 61, and the drain voltage considering the ambient temperature is applied from the drain bias regulator 61 to each drain electrode D of the MMICs 40-1 to 40-n. Applied.

  Further, the bias adjustment of the gate voltage is performed as shown in FIG. 3 as a part of the adjustment test process at the time of product shipment. FIG. 3 is a diagram for explaining a case where the gate voltage is set by the bias adjustment system shown in FIG. 2 for one MMIC in a certain MMIC group.

  In FIG. 2, the bias adjustment of the gate voltages of the MMICs 40-1 to 40-n is sequentially performed from the MMIC 40-1 to the MMIC 40-n. When a drain voltage is applied to each drain electrode D of the MMICs 40-1 to 40-n as described above, in the current monitor 35, a voltage drop due to the drain current appears at both ends of the shunt resistance element 38, and the voltage comparison circuit 39 Thus, the voltage V across the shunt resistor element 38 is obtained. This voltage V is input to the control processing unit 54 via the A / D converter 62. The control processing unit 54 reads the resistance value R of the shunt resistance element 38 stored in the memory 56 and obtains the drain current I by calculating I = V ÷ R.

  In FIG. 3, the control processing unit 54 first issues a gate voltage output command for the MMIC 40-1 to the gate setting voltage output unit 57. The gate voltage value output from the gate setting voltage output unit 57 is applied to the gate electrode G of the MMIC 40-1 via the D / A converter 64-1, and the gate setting voltage output unit 57 is controlled by the control processing unit 54. Until the stop command is input, the voltage applied to the gate electrode G of the MMIC 40-1 is gradually increased. An allowable range 71 is defined for the change ΔI of the drain current I of the MMIC 40-1. The control processing unit 54 monitors the change of the drain current I from the detection signal of the current monitor 35 as described above, obtains the change amount ΔI of the drain current I, and the change amount ΔI of the drain current I falls within the allowable range 71. When this is detected, a stop command is issued to the gate setting voltage output unit 57. When a stop command is input from the control processing unit 54, the gate set voltage output unit 57 holds the set voltage value 72 at that time as a determined value.

  The control processing unit 54 executes the MMIC 40-2 in the same procedure as described above in a state where the gate setting voltage value determined as described above is applied to the gate electrode G of the MMIC 40-1. The following MMIC 40-3 is similarly performed in a state where the gate setting voltage value determined as described above is applied to the gate electrodes G of the MMIC 40-1 and the MMIC 40-2. Thereafter, each gate voltage up to the final MMIC 40-n is sequentially set in a state where the gate voltage setting value is applied to each previous MMIC.

  In this manner, the control processing unit 54 performs the drain voltage and gate voltage bias setting process for the three MMIC groups. Next, the abnormality monitoring operation in the actual operation process will be described with reference to FIGS. In this embodiment, (1) transmission power monitoring by the current monitor 35 and the ambient temperature monitor 36 (FIGS. 4 to 6), and (2) drain current monitoring by the current monitor 35 (FIGS. 7 and 8) (3) The drain voltage can be monitored by the ambient temperature monitor 36 (FIGS. 9 and 10), and (4) the ambient temperature of the MMIC can be monitored by the ambient temperature monitor 36 and the DVC monitor 37 (FIGS. 11 and 12). It is like that.

  (1) In transmission power monitoring, it is monitored whether or not the transmission power of the FMCW radar is within the standards defined by the Radio Law and specifications, and whether or not the detection performance as a radar system can be maintained. . In this embodiment, the transmission power of the FMCW radar is not actually monitored, but the normality of the transmission power is determined using the monitoring results of the current monitor 35 as shown in FIGS. FIG. 4 is a flowchart for explaining the transmission power monitoring operation. FIG. 5 is a diagram for explaining the contents of the processing procedure for obtaining the current-type threshold value for decreasing and increasing the transmission power shown in FIG. FIG. 6 is a diagram for explaining the contents of the determination procedure for determining whether or not it is normal as shown in FIG. The MMIC that affects the transmission power is a frequency-multiplication MMIC group that constitutes the VCO 31. In monitoring the transmission power, the sum of the collector currents flowing through the frequency multiplication system MMIC group is taken from the current monitor 35 and determined.

  In FIG. 4, the control processing unit 54 reads the output of the current monitor 35 (step ST <b> 1), obtains the power value (step ST <b> 2), and gives it to the abnormality determination processing unit 58. As described above, the output value of the current monitor 35 is the voltage value V converted by the voltage comparison circuit 39, but since the resistance value R of the shunt resistor element 38 is known, the collector current I is I = V ÷ Since it is obtained by the calculation of R, the power value VI is obtained.

  When the abnormality determination processing unit 58 receives the power value from the control processing unit 54, the abnormality determination processing unit 58 refers to the memory 57 to take in the legal matters regarding the power, and determines whether or not it is a violation of the regulation (step ST3). If it is not a violation of laws and regulations (step ST3: No), the memory 57 is referred to take in the specification items regarding the power, and it is determined whether the specification is not in violation (step ST4). If the abnormality determination processing unit 58 is in violation of the regulations (step ST3: Yes) or the specification is violated (step ST4: Yes), the abnormality determination processing unit 58 issues an instruction to the abnormality result output unit 59 to make the transmission power abnormality external. It is notified (step ST5), and it is monitored whether the determined abnormal state continues for a predetermined time (for example, 10 minutes) or longer (step ST6).

  If the determined abnormal state does not continue for a predetermined time or longer (step ST6: No), the abnormality determination processing unit 58 ends the abnormality determination process as no problem, but if the determined abnormal state continues for a predetermined time or longer (step ST6: Yes) stops the operation of the millimeter wave transmission / reception module in order to avoid the occurrence of an operation error as a radar system (step ST7), and determines whether any other abnormality due to the ambient temperature abnormality has occurred. (Step ST8). Other abnormalities caused by the ambient temperature abnormality include drain current and drain voltage excess abnormality, junction temperature abnormality, and the like, which are determined by the respective monitoring routines.

  The abnormality determination processing unit 58 determines that repair is necessary if no other abnormality due to an ambient temperature abnormality has occurred (step ST8: No), that is, only a violation of regulations or only a violation of specifications. The determination process ends. On the other hand, if another abnormality has occurred (step ST8: Yes), the millimeter-wave transmission / reception module is restarted after the ambient temperature abnormality that is the cause is resolved (step ST9), and the abnormality determination process is terminated. To do. The “ambient temperature abnormality” is an abnormality in the upper and lower limits of the ambient temperature, and is determined by a monitoring routine for the junction temperature.

  In addition, the abnormality determination processing unit 58 outputs the output of the ambient temperature monitor 36 when the power value received from the control processing unit 54 is not in violation of laws and regulations (step ST3: No) and not in violation of specifications (step ST4: No). The current ambient temperature value is acquired from the control processing unit 54 that periodically performs capture (step ST10), and the transmission power decrease threshold value and increase threshold value are obtained by the procedure shown in FIG. 5 (step ST11). 6) It is determined by the procedure shown in FIG. 6 whether or not the current transmission power is normal, that is, the power that can maintain the detection performance of the radar system (step ST12). This will be described with reference to FIGS.

  In FIG. 5, the memory 56 stores in advance a relational characteristic 80 between the drain current I and the ambient temperature T shown in FIG. 5A and a relational characteristic between the transmission power P and the ambient temperature T shown in FIG. 81 are stored. 5A and 5B, the measurement points of the ambient temperature T are three points T1, T2, and T3 for convenience of explanation.

  The abnormality determination processing unit 58 obtains, for example, a relation characteristic 82 when the transmission power is increased by 30% and a relation characteristic 83 when the transmission power is reduced by 30% with respect to the relation characteristic 81 shown in FIG. Next, for example, when the ambient temperature detected by the ambient temperature monitor 36 is the temperature T2, the temperature Ta (Ta <T2) in the relational characteristic 81 corresponding to the ambient temperature T2 in the relational characteristic 82 when the transmission power is increased. Further, the temperature Tb (Tb> T2) in the relational characteristic 81 corresponding to the ambient temperature T2 in the relational characteristic 81 when the transmission power is reduced is obtained. Then, as shown in FIG. 5C, the abnormality determination processing unit 58 applies the obtained temperatures Ta and Tb to the relational characteristic 80 shown in FIG. A power current increase threshold value 85 is obtained. Similarly, a transmission power decrease current threshold value and a transmission power current increase threshold value at ambient temperatures T1 and T3 are obtained, and abnormality determination is performed according to the procedure shown in FIG.

  In FIG. 6, the ambient temperatures T1, T2, and T3 are ambient temperature values detected by the ambient temperature monitor 36. The current values I1, I2, and I3 are current values detected by the current monitor 35. The transmission powers P1, P2, and P3 are power values converted from the current values detected by the current monitor 35. Transmission power drop current threshold I1. max, I2. max, I3. max, and transmission power increase current threshold I1. min, I2. min, I3. min is the transmission power decrease current threshold value 84 and the transmission power increase current threshold value 85 obtained by the procedure described in FIG.

  At each measurement point of the ambient temperature T1, T2, T3, the normality of the transmission power is determined using the reduced current threshold value and the increased current threshold value obtained as described above. That is, when n = 1, 2, and 3, when In (current value)> In, max (transmission power decrease threshold), it is determined that the transmission power decrease is abnormal. When In, min (transmission power increase threshold) ≦ In ≦ In, max, it is determined that the transmission power is normal. When In <In, min, it is determined that the transmission power increase is abnormal. Thus, the normality of the transmission power converted from the drain current value measured at the current ambient temperature value is determined.

  Now, in step ST12 of FIG. 4, when the abnormality determination processing unit 58 determines that the transmission power obtained from the monitoring result of the current monitor 35 is a normal range value (step ST12: Yes), the abnormality determination processing is performed. If it is determined that the value is not within the normal range (step ST12: No), the abnormality result output unit 59 is instructed to notify the upper processing system of the transmission power abnormality (step ST13). It is monitored whether or not it continues for a predetermined period (for example, 10 minutes) (step ST14).

  When the determined abnormal state does not continue for a predetermined time or more (step ST14: No), the abnormality determination processing unit 58 ends the abnormality determination process as no problem, but when the determined abnormal state continues for a predetermined time or more (step) In ST14: Yes, the operation of the millimeter wave transmission / reception module is stopped to avoid the occurrence of an operation error or the like as a radar system (step ST15), and whether or not another abnormality due to an ambient temperature abnormality has occurred. Is determined (step ST16). When no other abnormality has occurred (step ST16: No), that is, when there is no violation of the law, no violation of the specification, and only the increase / decrease of the transmission power, the abnormality determination processing is performed according to the determination of the upper processing system. Exit. On the other hand, if another abnormality has occurred (step ST16: Yes), the millimeter-wave transmission / reception module is restarted after the ambient temperature abnormality that is the cause is resolved (step ST9), and the abnormality determination process ends. To do.

  (2) Next, in the monitoring of the drain current, since an excessive current may flow due to a short circuit failure or characteristic abnormality of the MMIC, or when the ambient temperature exceeds the rated value, the presence or absence of the excessive current is monitored. FIG. 7 is a characteristic diagram showing the relationship between drain current and ambient temperature. FIG. 8 is a flowchart for explaining the drain current monitoring operation.

  Since the control processing unit 54 adjusts and sets the drain voltage according to the monitoring result of the ambient temperature monitor 36, the drain voltage to be set increases as the ambient temperature increases. Therefore, as shown in FIG. 7, the drain current has a characteristic of increasing as the ambient temperature of the MMIC increases as the drain voltage increases. In this embodiment, an upper limit current value Imax as a sum of absolute maximum ratings in a certain MMIC group of a certain system is determined and set in the memory 56 at a certain temperature T (for example, room temperature 25 degrees) within a specified value range of the ambient temperature. The occurrence of excessive current is monitored by the procedure shown in FIG.

  In FIG. 8, the control processing unit 54 takes in the output of the current monitor 35, obtains the drain current value I, and passes it to the abnormality determination processing unit 58 (step ST21). The abnormality determination processing unit 58 determines whether or not the drain current value I received from the control processing unit 54 exceeds the upper limit current value Imax stored in the memory 56 (step ST22). As a result, the abnormality determination processing unit 58 ends the drain current monitoring process when I ≦ Imax (step ST22: No), but when I> Imax (step ST22: Yes), the abnormality result The output unit 59 is instructed to notify the outside of the transmission power abnormality (step ST23), and it is monitored whether or not the excessive drain current abnormality continues for a predetermined period (for example, 10 minutes) (step ST24).

  If the determined abnormal state does not continue for a predetermined time or more (step ST24: No), the abnormality determination processing unit 58 ends the abnormality determination process as no problem, but if the determined abnormal state continues for a predetermined time or more (step) (ST24: Yes) stops the operation of the millimeter wave transmitting / receiving module in order to avoid the occurrence of a failure (step ST25), and determines whether another abnormality due to an ambient temperature abnormality has occurred (step ST26). ). Other abnormalities caused by the ambient temperature abnormality here are excessive drain voltage abnormality, MMIC junction temperature abnormality, and the like. When no other abnormality due to the ambient temperature abnormality has occurred (step ST26: No), that is, when there is only an excessive drain current abnormality, the abnormality determination process is terminated as repair is necessary. On the other hand, if another abnormality due to the ambient temperature abnormality has occurred (step ST26: Yes), the millimeter-wave transmission / reception module is restarted after the ambient temperature abnormality causing the abnormality is resolved (ST27). ), And ends the abnormality determination process.

  (3) Next, in monitoring the drain voltage, an excessive drain voltage may occur when the drain bias regulator 61 is short-circuited, the MMIC characteristic is abnormal, or the ambient temperature exceeds the rated value. Monitor for voltage generation. In addition, when a short circuit failure occurs in the MMIC, an excessive decrease in the drain voltage may occur. Therefore, the excessive decrease in the drain voltage is also monitored. FIG. 9 is a characteristic diagram showing the relationship between the drain voltage and the ambient temperature. FIG. 10 is a flowchart for explaining the drain voltage monitoring operation. FIG. 10 shows a case where an excessive abnormality of the drain voltage is monitored.

  Since the control processing unit 54 adjusts and sets the drain voltage according to the monitoring result of the ambient temperature monitor 36, the drain voltage to be set increases as the ambient temperature increases. Therefore, as shown in FIG. 9, the drain voltage has a characteristic that increases as the ambient temperature of the MMIC increases. In this embodiment, an upper limit voltage value Vmax as a maximum applied voltage (absolute maximum rated value) to an MMIC group of a certain system is determined at a certain temperature T (for example, room temperature 25 degrees) within a specified value range of the ambient temperature. The setting is made in the memory 56, and the occurrence of excessive voltage is monitored by the procedure shown in FIG. Therefore, when monitoring whether or not the drain voltage is excessively lowered, the lower limit voltage value may be determined and set in the memory 56.

  In FIG. 10, the control processing unit 54 takes in the output of the ambient temperature monitor 36 (step ST31), extracts the drain voltage value V corresponding to the ambient temperature value from the memory 36, performs resetting, and resets the drain voltage. The value V is passed to the abnormality determination processing unit 58 (step ST32). Abnormality determination processing unit 58 determines whether drain voltage value V received from control processing unit 54 exceeds upper limit voltage value Vmax stored in memory 56 (step ST33). As a result, when V ≦ Vmax is satisfied (step ST33: No), the abnormality determination processing unit 58 ends the drain voltage monitoring process with no problem, but when V> Vmax (step ST33: Yes). Then, the abnormality result output unit 59 is instructed to notify the drain voltage upper limit abnormality to the outside (step ST34), and it is monitored whether or not the drain voltage upper limit abnormality continues for a predetermined period (for example, 10 minutes) (step ST35). ).

  If the determined abnormal state does not continue for a predetermined time or longer (step ST35: No), the abnormality determination processing unit 58 ends the abnormality determination process as no problem, but if the determined abnormal state continues for a predetermined time or longer (step) (ST35: Yes) stops the operation of the millimeter wave transmission / reception module in order to avoid the occurrence of a failure (step ST36), and determines whether another abnormality due to an ambient temperature abnormality has occurred (step ST37). ). Other abnormalities caused by the ambient temperature abnormality here are excessive drain current abnormality and MMIC junction temperature abnormality. If no other abnormality due to the ambient temperature abnormality has occurred (step ST37: No), that is, if there is only an excessive drain voltage abnormality, the abnormality determination process is terminated as repair is necessary. On the other hand, if another abnormality due to the ambient temperature abnormality has occurred (step ST37: Yes), the millimeter-wave transmission / reception module is restarted after the ambient temperature abnormality is resolved (S38), and abnormality determination processing is performed. Exit.

  (4) Next, in the monitoring of the ambient temperature of the MMIC, if the ambient temperature exceeds the rated value, the junction temperature of the MMIC rises above the maximum value, and the ambient temperature is within the rated value range. Even in such a case, the junction temperature of the MMIC may rise beyond the maximum value due to abnormal characteristics of the MMIC, so the ambient temperature is monitored so that the MMIC does not fail. In the monitoring of the ambient temperature of the MMIC, an ambient temperature abnormality that cannot be detected by monitoring the drain current or drain voltage can be monitored. FIG. 11 is a diagram for explaining a procedure process for checking whether or not the junction temperature of the MMIC exceeds the maximum value. FIG. 12 is a flowchart for explaining the monitoring operation of the ambient temperature of the MMIC.

  In FIG. 11, the vertical axis indicates the ambient temperature of the MMIC, and the horizontal axis indicates the junction temperature of the MMIC. As shown in FIG. 11, in the monitoring of the ambient temperature of the MMIC, the temperature value 87 monitored by the ambient temperature monitor 36 is within the rated value range and is not abnormal in the ambient temperature upper limit, but the temperature monitored by the DVC temperature monitor 37. When the value 88 exceeds the specified value, the junction temperature of the MMIC is the maximum junction temperature Tj. Since there is a high possibility of exceeding the maximum value, the maximum junction temperature Tj. For example, max is set and monitored by the procedure shown in FIG.

  In FIG. 12, the control processing unit 54 takes in the output of the ambient temperature monitor 36 and passes the ambient temperature value to the abnormality determination processing unit 58 (step ST41). The abnormality determination processing unit 58 determines whether or not the ambient temperature value received from the control processing unit 54 is within the rated value range of the ambient temperature value stored in the memory 56 (step ST42).

  When the ambient temperature value received from the control processing unit 54 is within the rated value range (step ST42), the abnormality determination processing unit 58 instructs the control processing unit 54 to capture the output of the DVC temperature monitor 37, and performs control processing. It is determined whether the output of the DVC temperature monitor 37 received from the unit 54 exceeds the rated value (step ST43). As a result, when the output of the DVC temperature monitor 37 does not exceed the rated value (step ST43: No), the abnormality determination processing unit 58 ends the abnormality monitoring process with no problem.

On the other hand, when the output of the DVC temperature monitor 37 exceeds the rated value (step ST43: Yes), the abnormality determination processing unit 58 sets the junction temperature Tj of the MMIC to
Tj = Ta + θja × P (2)
It calculates using the following formula (2) (step ST44). In equation (2), Ta is the monitored ambient temperature, θja is the thermal resistance, and P is the power consumption of the MMIC.

  The abnormality determination processing unit 58 calculates the maximum junction temperature Tj. In which the calculated junction temperature Tj is stored in the memory 56. It is determined whether or not max is exceeded (step ST45). As a result, the calculated junction temperature Tj is equal to the maximum junction temperature Tj. When it does not exceed max (step ST45: No), the abnormality determination processing unit 58 ends the abnormality monitoring process with no problem.

  On the other hand, the calculated junction temperature Tj is equal to the maximum junction temperature Tj. When it exceeds max (step ST45: Yes), the abnormality determination processing unit 58 issues an instruction to the abnormality result output unit 59 to notify the joint upper limit abnormality to the outside (step ST46). Then, since it occurred when the ambient temperature is normal, the operation of the transmission / reception module is stopped (step ST47), and the abnormality monitoring process is terminated as it is left to repair.

  Further, in the previous step ST42, when the ambient temperature is out of the rated value range (step ST: No), the abnormality determination processing unit 58 issues an instruction to the abnormality result output unit 59 to increase the upper limit of the ambient temperature. A lower limit abnormality is notified to the outside (step ST48), and it is monitored whether the upper limit / lower limit abnormality of the ambient temperature continues for a predetermined time (for example, 10 minutes) or more (step ST49). Then, when the upper limit / lower limit abnormality of the ambient temperature does not continue for the predetermined time or longer (step ST49: No), the abnormality determination processing unit 58 ends the abnormality monitoring process as no problem, but the upper limit / lower limit abnormality of the ambient temperature is detected. When continuing for a predetermined time or longer (step ST49: Yes), the operation of the transmission / reception module is stopped in order to avoid the occurrence of a failure (step ST50), and waiting for the ambient temperature abnormality to be resolved (step ST51) When the temperature abnormality is resolved (step ST51: Yes), the transmission / reception module is restarted (step ST52), and the abnormality monitoring process is terminated.

  Although the ambient temperature monitor 36 and the DVC temperature monitor 37 have been described as providing the thermistor in the immediate vicinity of the high frequency circuit 3, it goes without saying that the thermistor may be provided inside the high frequency circuit 3. If the ambient temperature monitor 36 and the DVC temperature monitor 37 are provided inside the high frequency circuit 3, the ambient temperature value and the DVC temperature value of the high frequency circuit 3 can be detected more accurately. Of course, the installation location of the current monitor 35 may be inside or outside the high-frequency circuit 3.

  Thus, according to this embodiment, in the millimeter-wave transceiver module itself, transmission power that gives a characteristic index of a device that uses the millimeter-wave transceiver module, drain current, drain voltage of the MMIC in the millimeter-wave transceiver module, and Since the junction temperature can be monitored and a notification can be given when an abnormality is detected, the monitoring burden on the host processing system can be reduced.

  At this time, in the transmission power abnormality monitoring, the MMIC group of the multiplying system in the VCO 31 is targeted. However, in the abnormality monitoring of the drain current, drain voltage, and junction temperature of the MMIC, the transmission MMIC group and the reception MMIC group are monitored. 1 and the multiplying MMIC group in the VCO 31, the circuit scale increases, but the bias circuit 6 has a configuration suitable for the integration of an integrated circuit. As shown, the signal processing circuit 5 and the bias circuit 6 that are peripheral circuits of the high-frequency circuit 3 can be integrated into an integrated circuit as an exclusive integrated circuit (ASIC) 6, and the size can be reduced.

  Regarding the circuit integration, the current monitor 35 is described as being provided in the high-frequency circuit 3 as a whole because it includes the shunt resistor element 37 that generates heat. However, the voltage comparison circuit 38 may be provided on the bias circuit 6 side. .

  Further, in this embodiment, an example in which the microcomputer 51 which is the main circuit part of the signal processing circuit 5 is provided with the main function part of the bias adjustment system and the abnormality monitoring function (configuration of the microcomputer 51 shown in FIG. 2) is shown. However, the main function unit of the bias adjustment system and the abnormality monitoring function may be provided independently. Even in this case, similar actions and effects can be obtained.

  As described above, the transmission / reception module according to the present invention is useful for monitoring abnormality in the transmission / reception module itself, and particularly suitable for use in a millimeter wave radar having such a demand because it can be downsized. It is.

DESCRIPTION OF SYMBOLS 1 Transmitting antenna 2 Receiving antenna 3 High frequency circuit 4 Dedicated integrated circuit (ASIC)
5 Signal processing circuit 6 Bias circuit 35 Current monitor 36 Ambient temperature monitor 37 Device (DVC) monitor (MMIC junction temperature upper limit monitor)
38 shunt resistance element 39 voltage comparison circuit 40-1 to 40-n MMIC (monolithic microwave integrated circuit)
54 Control processing unit 55 Drain setting voltage output unit 56 Memory 57 Gate setting voltage output unit 58 Abnormality determination processing unit 59 Abnormal result output unit 61 Drain bias regulator 62, 63, 64 A / D converters 65-1 to 65-n D / A converter

Claims (3)

A high-frequency circuit connected to a transmission / reception antenna of a radar that transmits and receives millimeter-wave radio waves;
A signal processing circuit for generating a transmission radio wave in the high-frequency circuit and processing a reception signal input from the high-frequency circuit;
A current monitor for detecting a drain current flowing through the high-frequency circuit;
An ambient temperature monitor for detecting the ambient temperature of the high-frequency circuit;
In a millimeter-wave transceiver module comprising
During operation, a transmission power value is obtained from the detected current value of the current monitor, and at least whether or not the obtained transmission power value is within a range of a predetermined upper limit value and lower limit value at the detected temperature of the ambient temperature monitor. Transmission power monitoring means for determining
A millimeter-wave transceiver module characterized by comprising: In determining whether the transmission power monitoring means is a power value that can maintain the performance required for the radar,
As reference data, a first characteristic indicating a relationship between drain current and ambient temperature and a second characteristic indicating a relationship between transmission power and ambient temperature are prepared in advance.
The third characteristic indicating the relationship between the transmission power in the second characteristic and the ambient temperature, which is shifted by a predetermined ratio preset on the upper side, and the predetermined ratio preset on the lower side, with respect to the transmission power in the second characteristic Create a fourth characteristic that shows the relationship between transmission power and ambient temperature,
Obtaining a temperature T1 in the second characteristic corresponding to the current ambient temperature in the third characteristic and a temperature T2 in the second characteristic corresponding to the current ambient temperature in the fourth characteristic;
Applying the determined temperatures T1 and T2 to the first characteristic to determine a transmission power increase current threshold value due to the temperature T1 and a transmission power decrease current threshold value due to the temperature T2,
When the current value detected by the current monitor exceeds the transmission power increase current threshold, it is determined as transmission power increase abnormality, and when it is below the transmission power decrease current threshold, it is determined as transmission power decrease abnormality, When it is between the transmission power increase current threshold and the transmission power decrease current threshold, it is determined that the transmission power is normal.
The millimeter-wave transceiver module according to claim 1.   The transmission power monitoring means also determines whether or not the transmission power value obtained from the detected current value of the current monitor is a violation of regulations or a violation of specifications. Millimeter wave transceiver module.

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