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  1. M

    About the influence of the speaker ,motor to the antenna .

    Hi , Since the cell phone get smaller and smaller ,so sometimes the antenna is very close to the speaker and motor , strongly impact the antenna efficiency ,cause the TRP and TIS poor . So anybody has the comments to decrease the influence of the speaker and motor ? Best regards !
  2. M

    The influence of the inductor to the antenna .

    Hello guys : Anybody know why add a series inductor on the input signal line of speaker can reduce the impact to the antenna .?Appreciate !
  3. M

    About the condutive spurious for GSM 900 band inside ?

    Hello guys : Anybody has the idea for the condutive spurious for Gsm 900 band inside ? We tested on the Chanel 62 ,found on the frequency 896.4 and 900.6, 904.2 was marginal . What do you think maybe impact this issue , Vco ,PA and tranceiver ouput matching to the PA ? Best...
  4. M

    The ORFS for 8-pslk issue

    orfs edge Dear Guys : These days we find the ORFS due to modulation and switching is very poor for EDGE 8-psk ,but for the GMSK is very good . I have checked all the power supply both for the Tranceiver and PA ,no found something wrong . Could you please give me some suggestion ...
  5. M

    About the modulation for the DVB-H ?

    Hello guys : These days ,we found the DVB-H has the modulatio scheme : QPSK ,16QAM ,OFDM . Why need these 3 modulation ? what is the relationship between the 16QAM and OFDM ? I am confusion .Best regards.
  6. M

    About the egde measurement ?

    Hi Guys : I am very new for the Edge handsets development , any guys has the spec for the Edge test and measurement guide ? Best Regards !
  7. M

    About the antenna switch ?

    Hello guys ! What maybe influence the attenuation of the antenna switch low pass filter ?The spec say the attenuation is 30db for 2nd harmonic and 3rd harmonic in normal .But in practical layout ,the attenuation is much lower than spec , what maybe decrease the attenuation ? Best regards !
  8. M

    How to get practical capacitor and inductor models for ADS?

    About ADS ? Hi ,any gays know how to download the practial capacitor and inductor model for ADS ?For example ,Muratar or TDK ? Best regards !
  9. M

    About power controlol in WCDMA ?

    power control & wcdma & dynamic range WCDMA ,what is difference between open loop and inner loop power control ? And ,when use the open loop ? when use the inner loop ? Best regards !
  10. M

    About mentor boardstatio ?

    Hello ,guys ! Anybody knows the link of the mentor boardstation material ? Best regards !
  11. M

    About switching transient issue ?

    Hello . These days , I fonud the switching transient failed . But the fiailed was not caused for the ramping up or ramping down too fast . It is at the useful portion of the power ramp .Any guys know what maybe cause these issue ? Best regards !
  12. M

    Hello ,what maybe affect the switching transient?

    What maybe cause the switching transient failed ? PA poer supply ? The match of the PA output ? Hope your comments !Best regards !
  13. M

    What may cause VCO pulling?

    Guys , what maybe cause the VCO pulling? I find the peak phase error for the first bite is very high . Maybe the power from power amplifier feedback to the VCO , cause the frequency pulling .But I don't know what cause this issue . Any guy, can provide some suggestion ?Best regards !
  14. M

    Problem with DCS band 2nd and 3rd harmoinc

    About the harmoinc ? Hello guys ! I found the DCS band second harmonic and 3th is very high for the mobile .I try tuning the match network from PA to switch ,but no improvemet ! I also find that is very high from tranceiver ,no pass PA . Now ,I have no idea !Any guys can give me some...
  15. M

    Hello ,about the 50 ohms microstrip !

    Hello ,guys . Anybody knows how to confirm the impedance of the microstrip ? For example ,I have simulated the width of the microstrip for 50 homs .But I don't know whether the impedance of pcb tracks from pcb manufactory is correct ? How to confirm ? Best regards !
  16. M

    About match network from PA to switch ?

    Any guys konws how to make a match network from PA to switch ?
  17. M

    Any guys know about WCDMA ?

    At the present , we prepare for desinging the WCDMA mobile phone . But that is very poor for me .It is the first time to desing the WCDMA . Any body knows the test item in detail ,and the experience to debug ? Best regards !
  18. M

    looking for good books for balance impedance matching !!

    I want to make match for balance . But I don't know how to start ? How to measure the balance impedance by network analyzer ? What is difference from single ended ? Best regards !!
  19. M

    Measuring impedance for balance output by network analyzer

    about impedance measure? Hi , How to measure impedance for balance output by network analyzer ? What is difference from the single output measure? Best regards !!
  20. M

    Hi, about harmonic question?

    When I added a matching network at DCS band ,the GSM 2nd (about 1.8048G) harmonic get very bad ,very close to the limit -30dbm. But I removed the added the matching , the harmonic getting better about -45dbm . The matching network can improve the...

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