Digital Directional Antenna
Technology Revolutionize AM and FM Radio Reception
In 1997, Blaupunkt introduced its first car stereo with DigiCeiver®, the world’s first and still only widely available AM/FM radio tuner that converts incoming analog radio waves into digital data. By digitizing incoming radio frequency signals, DigiCeiver can use advanced digital signal processing (DSP) techniques to refine the signal quality in ways not possible using analog circuits. The result is outstanding radio reception and sound quality delivered at greater distances. This performance has been confirmed by dozens of reviewers, some of who said DigiCeiver was superior to some expensive home reference tuners.
Now, Blaupunkt has introduced the next big step in digital radio processing, TwinCeiver. TwinCeiver uses two DigiCeiver tuners and a Digital Directional Antenna (DDA) to combine the signals from two antennas, and forms a virtual directional antenna that provides a much stronger signal from the desired direction, and an attenuated signal from unwanted directions. The result is dramatically improved range, sound quality, and rejection of multipath interference.
TwinCeiver operates on a completely different principle than the widely used two-antenna “diversity” receivers, which merely compare the signals from both antennas and then chooses the best one. Since the length of FM radio waves is very short, the only way the signals from two antennas can normally be combined is if both travel the exact same distance from the broadcast tower to the radio input. If the paths are only a few inches different, the signals will arrive at the radio input out of phase with each other and cause serious interference.
While DDA’s directional capabilities will eliminate most multipath interference, there may be rare occasions when one antenna gets a fairly good signal, while the other’s is totally unusable. In this case, the inferior antenna is shut off to maintain the best signal in the tuner.
TwinCeiver also has Radio Data System (RDS) and Traffic Message Channel (TMC) background reception mode that takes advantage of optimal reception conditions to quickly and inaudibly access RDS channels on different frequencies for station and format lists without interfering with the audio. (This is more important in Europe and other areas where RDS capabilities are much more widely used than in the USA. TMC is not used at all in the USA, Canada or Mexico.)