Patent ID: 7693505
Filing Date: 2010-04-06
Classification: H04B

Abstract:
1. A signal detector for locating the presence of a signal transmission and identifying the signal comprising: a radio frequency receiver, which receives an external radio frequency signal; a filter, which filters said radio frequency signal; a signal amplifier, which receives said filtered radio frequency signal and outputs said amplified signal; a direct-conversion-receiver, which receives said amplified radio frequency signal and transforms said amplified radio frequency signal directly to a baseband signal; a data converter, which comprises: a background-noise filter, a reference-noise value generator, and a level comparator; wherein, said background-noise filter receives the voltage or current signal corresponding to said baseband signal, and outputs a reference-noise value to be filtered; after passing through said background-noise filter, a signal is outputted to said level comparator and compared with a pre-determined level value, then if the level of said filtered signal is bigger than said pre-determined level value, said filtered signal is outputted; a memory device, which stores said pre-determined level values of said level comparator; a microprocessor, which receives said filtered signal, wherein said microprocessor outputs an instruction to said reference-noise-generator, so said reference-noise-generator can produce different reference-noise values depending on diverse background noises; furthermore, when said microprocessor receives said filtered signal, a warning device will be driven and switched on; and a protocol comparator that includes a protocol database; said protocol database receives said filtered signal and outputs a protocol confirmation signal to said microprocessor to notify what kind of protocol the confirmation signal is, including OSM, GPRS and signals of transmitting images, after proceeding with protocol comparison, wherein said microprocessor obtains a protocol of said external radio frequency signal according to said protocol confirmation signal, wherein said signal detector comprises a level adjuster connecting to said microprocessor to control said pre-determined level value of said level comparator in such a manner that, when said level comparator outputs said filtered signal due to the level of said filtered signal being bigger than said pre-determined level value, the level adjustor increases said pre-determined level value gradually and wherein the receiving range of said radio frequency receiver is 30 MHz to 6 GHz.