KEXINSHE KC901J User Manual

Handheld dual-port vector network analyzer

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科创仪表局

KECHUANG INSTRUMENT ASSOCIATION

(test

line)

first edition

Kexinshe

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Summary of Contents for KEXINSHE KC901J

Page 1 科创仪表局 KECHUANG INSTRUMENT ASSOCIATION (test line) first edition Kexinshe...
Page 3 5KHz...2/4/7/9.8GHz, 1...22GHz KC901J/K/R/T/B...
Page 4 Mechanical Engineer Li Yun (BI8DPN) Process Engineer Yuan Xinzhi Author(s): Liu Hu Translator: Wu Xiao (BG8NPK) Publisher: KeXinshe Contact us: 028-86691700 First edition, May 2023 Opening: 890×1240 1/32 First printing May 2023 Print: 1 Print run: 1-100 Words count: 30k...
Page 5 KC901x is not a consumer product and the user must be a professional or have specialized knowledge. In this manual: Hazard Indicates that personal injury, significant risk, equipment damage, or other serious consequences may result. Warnings Indicates that incorrect measurement results or general hazards may occur.
Page 6 Please bring it into the cabin when you fly, remove the antenna, set it to the spectrum mode and turn off the power. If local regulations and airport regulations contradict this manual, transport by other means. The KC901x has a maximum charge capacity of 60 Wh. It is necessary to use qualified batteries, to store them properly according to their characteristics, and to anticipate the risk of combustion and explosion of lithium batteries.
Page 7 some frequency bands can also be field strength measurement, interference finding and other work. KC901x is a good tool for learning RF knowledge. In the professional field, it can be used in communication engineering, antenna manufacturing, daily maintenance of radio and television transmitters and RF circuit research and development, which can effectively improve operational efficiency, reduce the burden of carrying and improve the quality of work.
Page 8 Chengdu Kechuangshikong Tech.Co.Ltd. is authorized by Kechuang Institute and is responsible for the product development and production of KC901x. Sichuan Kexinshe Tech Co.Ltd. is authorized by Kechuang Institute and is responsible for the domestic sales of KC901x. Guangdongshenkong Co.Ltd. is authorized by Kechuang Institute and is responsible for the international sales of KC901x.
Page 9 Table of Contents Security matters ......................... I Preamble ............................. II Chapter 1, Overview ........................ 1 1.1,Theory .......................... 2 1.2,Main parameters ....................... 5 1.3,Charging time and Battery life ................5 Chapter 2, installation guide ....................7 2.1,Battery selection ......................7 2.2,Install the battery ...................... 7 2.3,Installation of shoulder straps ................
Page 10 4.8,Use of external coupler ..................33 Chapter 5,Common Test Methods ................... 35 5.1,Preparation before testing .................. 35 5.2,Adjustment of duplexer ..................36 5.3,Test Antenna ......................40 5.3.1,Antenna standing wave test ..............40 5.3.2,Cable deduction ..................41 5.3.3,antenna impedance test ................41 5.3.4,Simple test of antenna gain, directional map ........
Page 11 Since 2022, we have systematically summarized the pros and cons of previous products, combined with the problems commonly reported by users, carefully organized the design work, and planned to launch KC901J, K, R, T, B and other models. The fourth generation 901 changed from the previous 1½ ports to full...
Page 12 Model KC901J KC901K KC901R KC901T KC901B Frequency 5k~2GHz 5k~4GHz 5k~7GHz 5k~10GHz 1G~22GHz range For base-wave mixing network analyzer, it can be used as a simple signal source, field strength meter, comparator and spectrum meter, although the performance is a little lower than the corresponding specialized instruments, but it can completely help to solve practical problems.
Page 13 test respectively, compare them, and get the S-parameter by calculation. The diagram at the figure2-1 shows the RF block diagram of the KC901. Taking and S of the measurement two-port device as an example, the path of the excitation signal is shown in red. After being generated by the frequency source, it is conditioned by the step attenuator and bypassable amplifier, and the forward reference signal R1 and reverse signal A are extracted through the forward and reverse couplers, outputted to the device under test (DUT) through port 1,...
Page 14 processed by the second IF filter and the ADC driver amplifier and finally sent to the ADC for sampling. If the S and S of the device need to be measured, the excitation signal is output from port 2 and the amplitude difference and phase difference of the three signals R2, B and A are measured.
Page 15 KC901B 45dB Receiver J/K/R/T -130dBm/Hz normalized KC901B -136dBm/Hz noise floor dynamic J/K/R/T 100dB RBW:1kHz range KC901B 110dB KC901J/K 27dB Coupler absolute KC901R/T 23dB directionality KC901B 16dB Trace noise RMS, 0.005dB straight through Scanning speed RBW:10kHz 0.8ms/pt Scanning points 10001...
Page 16 time is related to the battery capacity. At present, the largest capacity commercial battery, single capacity up to 3.4Ah, if loaded into 4 sections, charging time is 4/2 ×3.4≈7h. If only 2 sections of 2.2Ah capacity battery, charging time is about 2.5h. The instrument will automatically stop charging when the single battery voltage reaches 4.2V and the battery pack voltage 8.4V.
Page 17 Depending on the policies of different regions, the KC901x may be shipped from the factory without a battery installed and will need to be installed by the dealer or user. Before installing the battery, please power on the instrument with the power adapter and turn it on for inspection.
Page 18 the end (Figure 2-1). Step 2: Slide the case (the keyboard side) towards the end for about 2cm (Figure 2-2). The method is to squeeze your fingers hard on both sides of the upper case, while pulling the RF connector outward. If it is difficult to slide, you can lightly hit the tail of the lower cover on the wooden board.
Page 19 Figure 2-3, the direction of the battery and the order of installation Step 5: Check the data cable plug, if there is an offset misalignment, it needs to be reinserted. Step 6: Close the case according to the opposite steps and press the POWER button to turn on the power for inspection.
Page 20 abdomen). If it needs to be used on the move, it is recommended to carry it upside down. When running, the shoulder strap should be shortened and worn diagonally across the shoulder, beware of the damage caused to the body. The instrument is designed to be held in the left hand and operated by the right hand.
Page 21 The designers of KC901x have made a lot of efforts to make it easy to understand. Except for the keyboard which needs to be adapted, the fourth generation product retains almost all the operating habits of the previous products, and users with basic knowledge can be familiar with it after only one or two days of use.
Page 22 level in the spectrum function, and adjust the output amplitude in the signal source function. MARK Access to the marker function menu HOME Enter the function selection menu. Press repeatedly to toggle between the function selection menu and the function menu. STOP/RUN Stop scanning, start scanning +, -...
Page 23 SHIFT+6 Switch button beep SHIFT+7 Switching resolution bandwidth (RBW, 1k, 10k) SHIFT+8 Switching sweep points (101, 401, 1001) SHIFT+9 Switching scanning speed (fast, medium, slow), the slower the more stable SHIFT+. Save current user calibration data SHIFT+0 Reads user calibration data SHIFT+ENTER Locking keypad and knobs to prevent misuse Table 3-2...
Page 24 If the core pin is protruding or bent, it must be repaired before connection. However, there is no need to connect unnecessary adapters to protect the port. The more adapters you connect, the less accurate the measurement will be. The design life of the port is 1000 times unplugged, the aging of the port has a certain impact on the accuracy of vector measurement, and should be replaced in time after exceeding the life.
Page 25 Figure 3-4, Display Zone The instrument has five basic functions: S-parameter test (S11/S21/S12/S22), spectrum (SPEC), field strength meter (FIELD), RF signal source (RF SOURCE), and audio signal source (AF SOURCE). As software development progresses, time domain functions and dual-port comparators may also be provided. All functions other than S-parameter measurement are informal functions based on the complimentary network analyzer architecture.
Page 26 Figure 3-5, The display mode setting options on the main menu of the mode To enter: Press the HOME key, then press the S parameter option in the menu, for example (S11). The port number of the S parameter obeys the number printed on the panel and cannot be specified by software.
Page 27 To enter: press HOME, press FIELD option in the menu, and then press Insertion option, so that the bottom right corner of the screen shows "GEN ON (tracking source on)". When the insertion loss test is turned on, the measurement port selected in the field strength mode is also the input port for insertion loss.
Page 28 the output attenuation, the smaller the modulation system can be used. The port of the RF source can be specified in the software. The output amplitude of both ports is the same. Except for the KC901B, the output amplitude of the RF signal source of the fourth generation KC901 is smaller than that of the third generation because the signal must pass through the coupler.
Page 29 changed when it is stopped. Due to the lack of warm-up time, the results of a single sweep have a slightly larger error. When more accurate data is required, please adjust to auto- sweep status. In the Spectrum (SPEC) and Field Strength (FIELD) functions, there is an Local Oscillation Mode for determining the mirror response.
Page 30 after pressing CENT. To set the sweep width, press the SPAN button. The start frequency (START) can be set with the key combination SHIFT+CENT. The cutoff frequency (STOP) can be set with the key combination SHIFT+SPAN. If you are accustomed to entering frequencies in the start and stop frequency mode, you can select the Frequency Control option as "Start Stop"...
Page 31 is used to toggle the vertical coordinate span. The field strength mode actually measures the level of the input port. The field strength value is calculated from the input level and the antenna coefficient. The antenna coefficient is mainly related to the frequency and antenna gain. Therefore, to get the correct field strength reading, the antenna gain must be told to the instrument.
Page 32 screenshot of the current screen and save the test results and settings as a number table. The above file names for saving data are automatically generated by the system. I To write the file name manually, use the key combination SHIFT+ When connected to a computer with a USB cable, the instrument will virtually become a USB flash drive and the SD card is actually taken over by the computer, so no data can be stored when connected to the computer.
Page 33 The KC901x is factory calibrated on its own port to eliminate the need for calibration in the field. For various reasons, factory calibration cannot perfectly correct for errors in the field and curves can drift undesirably, but when performing general engineering applications, there is no need to spend time on specialized calibration as long as the test results help in analysis and judgment.
Page 34 system calibration through the "restore factory settings" function. System calibration: The instrument is shipped with the same system calibration data as the factory calibration. The system calibration is ready to use and allows the user to recalibrate. After performing a system calibration, the instrument will receive a basic error correction regardless of the frequency it is operating at, thus eliminating the need for calibration in most cases.
Page 35 S21 enhanced response calibration, S12 enhanced response calibration, full dual- port calibration, and TRL calibration (not yet available). Except for TRL calibration, the SOLT calibration model is used for all of them. Based on the principle of the calibration model, TRL calibration is only available for full two-port calibration. Step 2: Follow the procedure prompted by the instrument to connect the specified standard at the specified port, and press the Start button after the connection is made.
Page 36 L: load, matching the load calibrator, providing full absorption with zero reflection; T: through, thru, straight-through calibrator, provides known delay and almost zero loss. The actual calibrator is not likely to be completely ideal. In addition, there is a certain distance between the interface of the connector, or the phase reference plane, and the reflecting plane.
Page 37 calibrator, usually for the air line, which is quite troublesome. For simplicity, the straight-through calibrator can also be supported, but then there will be dielectric loss and some reflection loss, with more parameters, which are usually approximated by the loss of the specified frequency in engineering, or another way (for example, using a calibration model that supports unknown straight- through, but cannot cross octave, which is not convenient for broadband testing).
Page 38 through a connector that is never removed, preferably male to female, using a planar type connector or a waveguide direct connection. Therefore, the straight- through calibrator may not be present, and if it is, then it cannot be removed for subsequent calibration and testing.
Page 39 When calibrating at the remote end of the external cable, if the electrical length of the external cable is more than half of the wavelength corresponding to the frequency step (STEP), it is necessary to increase the number of scanning points (or reduce the SPAN) before calibrating in order to avoid phase overlap.
Page 40 order to eliminate the errors caused by multiple reflections between the DUT and the instrument (which usually make the curve ripple) and get the most accurate transmission parameters possible. Therefore, strictly speaking, a full two-port calibration should be performed even though in many cases only the transmission parameters need to be tested.
Page 41 If the device to be tested is light and small, allow one port of the device to be tested to be connected directly to the instrument. In this case, only one additional RF cable is needed to compose the test system. For cases where one cable is used, this cable should be connected directly across the two ports of the instrument (Figure 4-1) and perform a user calibration operation before the test begins.
Page 42 When testing power amplifiers, an attenuator should be connected in series with the output port of the amplifier to avoid high power entering the instrument. For small signal amplifiers, the output level of the instrument should be reduced (with the internal attenuator turned on), and if it is still not low enough, an attenuator should also be connected in series at the input of the amplifier to avoid too strong excitation signal.
Page 43 method in section 5.4, and the frequency band with a stable trend of phase change and as straight a phase frequency characteristic curve as possible should be selected for measurement. This measured electrical length usually extends to the feed point of the antenna, more effective for antenna debugging. If you can calibrate at the end of the feed cable, you can still use this method to extend the phase plane to the feed point.
Page 44 of the external coupler should be connected to port 2 (right side), or vice versa. It is recommended to connect an attenuator in series to improve matching. If the external coupler input is connected to port 1, the S11 function should be used for measurement, otherwise the S22 function should be used.
Page 45 This chapter gives a few examples, users can practice, experience and understand against it. (1) Confirm the battery level before using it outside. Let the device run and observe the voltage indication, if it is above 8.0V, it means there is still at least half power left.
Page 46 (7) The test of passive devices can be performed in the charging state, and the test of active devices should not be performed. If you insist on performing such a test, please take care to connect the ground of the 901x (the housing of the coaxial connector) to the ground of the device to be tested at equal potential.
Page 47 instrument has high output power and high dynamic range, suitable for adjusting duplexers such as more than 80dB notch filter. 401 sweep points, can ensure that STEP is small, the above example, STEP = 40MHz ÷ 400 = 100kHz. (3) Press SCALE to set the reference level to make the topmost coordinate is 0dB or 10dB and the coordinate span is 10dB/div.
Page 48 screws in turn under mark1's S reading monitoring so that the reading is the smallest (most negative). Under normal conditions, it should reach -70dB or more. At this point, mark1 indicates the HIGH side isolation, and mark2 indicates the HIGH side insertion loss. (7) Connect port 1 of the KC901x to the ANT port of the duplexer, port 2 is connected to the RX port, and the TX port is connected to the dummy load.
Page 49 principle of "TX inward and RX outward" should be followed to try to take into account the insertion loss. Figure 5-2: Typical curve of the LOW side of the duplexer, without compensation for cable loss If the insertion loss remains high, consider the S11 test (non-test port connected to a dummy load, should not be connected to the instrument input port) and try to adjust it to do a balance with other indicators to control the SWR to within 1.5.
Page 50 As long as the dynamic range allows, a 3dB attenuator can be connected in series with the input port of the instrument to improve matching. Warning The output port of the KC901x may produce more than 0dBm (1mW) and the KC901B may exceed 13dBm.
Page 51 housing of the instrument may become part of the antenna. When testing unbalanced antennas, appropriate fixtures must be used to stabilize the test environment, such as using a large metal plate as a reference ground. Do not connect the whip antenna directly to the instrument for testing. Refer to the application guide (KC document number 888909) for details.
Page 52 amplitude difference and phase difference are related to the feed line, user calibration must be performed at the feed point or at the end of the feed line. For printed circuit board antennas, if there is no coaxial interface, a thin coaxial cable can be used to lead the interface from the circuit board.
Page 53 distance reduction is allowed). If necessary, you can do multiple tests at different distances, take the linear average (can not directly average the decibel value), in order to eliminate the impact of ground reflection. According to the distance of the bracket, prepare a long enough cable, try to make the instrument and testers up to 10 times the wavelength from the antenna.
Page 54 measurement for post-analysis. To reduce the complexity of operation, KC901x automatically names the files in chronological order. If there are more files that are easily confused, SHIFT+3 can be used to store them, at which point the file names can be manually specified. If you want to test the gain of the antenna, you need to set up the reference antenna with known gain to the antenna bracket to be tested, adjust the orientation of the reference antenna and the test antenna (make the direction of...
Page 55 take the section of the curve with smooth curve and obvious periodicity, measure the length of the frequency difference (Δλ) experienced when the phase rolls exactly one circle (the frequency difference between the two cursors is close to 0 degrees), and divide by 2 to obtain the electrical length of the transmission line. It is also possible to measure the length of the frequency difference experienced at a phase shift of 180 degrees and divide it by 4, or measure the length of the frequency difference experienced at two 360 degrees and read the result directly.
Page 56 In the case of an open or short circuit at the termination of the cable, the cable loss is approximately equal to one-half of the return loss. The return loss at the non-operating frequency of the antenna, when the cable is connected with an antenna, can be used to initially assess the magnitude of the cable loss.
Page 57 If the frequency range is narrow, narrowband antenna should be used as much as possible. Set CENT, SPAN according to the frequency span to be measured. Set the reference level according to the strength of the signal to be measured (in the SCALE menu).
Page 58 Figure 5-4, Example of cross-positioning and graphical operations No matter what instrument is used, the orientation of the interference source is a combination of theory, experience and technology, and requires much practice to improve efficiency. In most tests, especially in urban or mountainous areas, there are numerous false directions due to the phenomenon of signal bypassing and reflection.
Page 59 Please peel off the protective film of the display. The display has been made of tempered glass panel, which is extremely wear-resistant and replaceable, so there is no need to post protective film to protect it, otherwise it will reduce the sunlight viewing effect.
Page 60 adapter and eliminate the influence of the adapter cable by calibration. (3) when installing the connector, should be aligned with the location, carefully inserted, lightly shake slowly screwed, feel the core pin into the core hole, and then tighten the threads. Screw threads should be operated with both hands, one hand holding the main body to avoid rotation, the other hand to rotate the screw sleeve, do not make the entire plug rotation.
Page 61 (11) Please do not disassemble the case at will. Slight carelessness in disassembly can damage the circuitry and such damage is not covered by the warranty. Disassembly of the RF components will forfeit all warranty rights. (12) The calibration cycle of the instrument is recommended to be 1 year. (13) The quality and safety guarantee period of the main unit is 1 year.
Page 64 KC901...

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