Commissioning method of the detector of phone jammer

The first RF SAW filter (optional band) should be the main consideration with low insertion loss: second RF SAW filter (optional channel) the main consideration with high selectivity; IF SAW filter to select a low insertion loss and good selectivity the device. BaLun also a very important high-frequency devices, should be measured to see whether it satisfied by the circuit design. RF Tx / RX switch IC and RF test socket must also be tested by the index, meet the design requirements. Commissioning method of the detector of phone jammer intelligent system will be described.
EMC design is a problem? Should enhance grounding, shielding and filtering measures. Process considerations: It should be noted PDB layout design, especially the front-end circuit design and layout characteristics of impedance matching design; should be noted that the SMT process parameters as inappropriate will result in some particular SAW filter RF Weld. Can be measured to determine whether the design requirements 13MHz TCX0, if you meet the requirements to replace or re-election of supporting manufacturers. AFC control software and control loop filter circuit design if there are problems. TCXO power supply circuit design is a problem, according to θ = ωt, we know: the time error and phase error and frequency error has a relationship, therefore, the frequency synthesizer phase noise and lock time will affect the index. If the frequency synthesizer lock time will lead to a corresponding noise increase, causing the phase error to increase, which is in need of GPRS applications seriously enough. Check the PA incentive power is enough? Any problem, can increase the excitation power; re-examination of the PA input and output matching circuit design is correct; key technical parameters of the device meets the PA requirements; inspection and testing of RF switches, directional couplers the antenna side of the RF test connector, PA power supply circuit is normal; check TX-VCO output level is adequate; APC control IC, APC table parameters in the control software and algorithms if there are problems.
Mobile phones transmit spurious indicators SRRC type approval test, is a very important, but also a more difficult by the technical indicators, it should be cause enough attention to the design engineer. Improved methods are as follows: to improve the quality of the modulation spectrum; to improve the quality of the spectrum switch; power Ramp slope not too steep, so as not to cause-of-band spectrum, spurious larger; Tx-VCO-band spectrum of indicators, with particular attention to second and third harmonic suppression indicator meets the design requirements of the machine; PA-band rejection indicators (mainly the second harmonic) meets the design requirements; PA PA input, especially the BPF or LPF output targets are met design requirements