Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
here is a problem about the spectrum of GSM .
A GSM Module , which power from external DC-DC regulator. as the osciallator of this DC-DC regualtor works around 400khz , when test GSM spectrum due to modulation , it fail on 400Khz . as its fixed working frequence of regulator , how to resolve...
When two bluetooth devices conncting , for example , phone with bluetooth function and bluetooth earphone. when making a call , there seems a bit "Pi-Pa" background noise from earphone . it seems worse when both devices are a bit away. how to debug it ? Our BT chipset is CSR BC4. thanks
Could u give some suggestion or guideline on inside antenna design inside a metal housing of a mobile phone? the antenna i design is monopole or PIFA . Do you think which is better for performance ? thans in advance.
Do u have some experiences on design a PIFA on the slide phone . what have to be concerned on the slide phone? and How to improve the sensitivity on this phone.
Any suggestion or information will be welcome.
I found there is a difference on PCS1900 time mask measument between CMu200 and 8960 . that happens on PCL13-14 . -6dbc of rise time mask will change to -1dbc on CMU200 , but it never change on8960 . Which measurement is right i will follow , CMU200 or 8960 ?
Time mask for PCS1900?
Are the spec of time mask for PCS same as the it of DCS1800 ? I found there is a difference on Low PCL between them . When PCL=15 , -6dbc will change to -1dbc on DCS , but it never change on PCS . Are they right ? they are from ENSI 0505.
When measuring the performance of mobile phone through radiation connect using CMU200. we need make a compensation on TX & RX Loss .we found some phones made this compensation , RX loss was biger than it on normal phone , while TX loss sometimes need a biger compensation than it on normal phone...
Do you ever check or explore the structure of samsung GSM phone ? We measured its sensitivity , it's very good when use inside antenna (slide phone)or outside antenna . i found it made some improvement on Grounding around FPC connecting, but its FPC only use single layer . Is there anyone can...
REQ: Sensitivity improve
I have a mobilephone , its housing is made of AL-Mg Alloy for solidity . but its sensitivity is bad on radiation mode , it;s only -95dbm on GSM and -99dbm on DCS/PCS . could you tell me how to improve it.?The materials of Al-Mg Alloy cause the sensitivity get bad, i...
I found some dimensions of holes are different on shielding case of mobile phones boards, and their locations are different . I know it deponds on wavelength of interested , but why some are a little biger and others a little smaller? Could u tell me the reasons?
I have a slide-phone with inside antenna , but GSM sensitivity is only -90dbm through the radiation , i also found FPC could improve it about 3dB through outside GNDing . Could u help me and give me some adivse or suggestion to hoe to improve it.thanks