Atmel Introduces AM/FM Antenna Impedance Matching IC For Enhanced Car-Radio Reception

Heilbronn, Germany -- Atmel Corporation announced the availability of the highly integrated AM/FM antenna amplifier IC ATR4251, which enables outstanding AM/FM car-radio reception when used with designer antennas, such as windshield, roof, or bumper antennas. The ATR4251's impedance matching amplifier helps to compensate for signal losses resulting from the smaller dimensions of modern antennas and the longer cables to the car radio.

The ATR4251 IC enables clear reception without distortion under difficult and rapidly fluctuating field strength conditions typically found in moving antenna systems. This high reception quality is due to the balance of an AM gain value of up to 35 dB, a large-signal behaviour both in AM and FM mode (e.g., IP3 148 dBuV in FM), and a good noise behavior, optimized for antenna applications.

A separate low-noise amplifier (LNA) for FM and a buffer amplifier for AM are used to address the different operating frequencies and requirements of both AM and FM. The AM amplifier covers the entire broadcasting frequency range from 150 kHz up to 30 MHz which includes modern DRM systems. The FM LNA handles the frequency range from 70 MHz to 166 MHz, which includes weather band and HD Radio in the US.

The automatic AM and FM gain control (AGC) enable independent AM and FM adjustment to prevent overdriving of amplifiers under large-signal conditions. In addition, the use of two separate AGC circuits stops strong AM signals from blocking FM stations, and vice versa.

"Car radio antennas are increasingly seen as an intrinsic element of car design," stated Carsten Friedrich, Marketing Manager Broadcast Radio at Atmel. "The ATR4251, without compromising on reception performance of car radios, directly addresses this challenging antenna design trend."

SOURCE: Atmel Corporation