mobile sensitivity

When test a PCBA through the test port near the anetena port about its sensitivity , it's good , but when put it into the house , and test its sensitivity through the anetena , it results in bad sensitivity . My phone is GSM and DCS1800 and PCS1900 with dual displays. i already judge that its LCD display (sub-board) results its bad sensitivity ,but don/t know how to debug and improve it, could u help me?

One possibility is the digital part is radiating into the antenna. Is this a new design or one sample of a commercial unit?

Can you temporarily turn off the display by cutting the trace from the logic clock and removing any timing capacitors of RC oscillators?

Yes , it's a new design , why remove any timeing capacitors of RC oscillators?