From EEProductCenter.Com:
An active antenna IC designed for AM/FM car antenna applications, the ATR4252 from Atmel Corporation is a highly integrated device that offers a host of features including automatic gain control (AGC), supply voltage regulator with overvoltage protection and an antenna sensor.
Designers can now develop smaller, high-performance active antenna solutions for applications located in the mirror, bumper, rear or side windows of a car. In addition, the antenna detection functionality is ideal for modern window or glass antennas. The robust IC also addresses other antenna types including window, pole or shark fin antennas with its small 4 x 5 mm footprint.
The chip is designed to provide low-noise and high linearity to ease antenna system design complexity. On-chip voltage regulation is an important feature when un-stabilized phantom feed is used, and 50 Ohm cable support enables more cost-effective cables to be used. Further, on-chip AGC avoids problems with large signals, while maintaining a high sensitivity level.
“Active antenna designs using ICs are becoming more popular since they offer many advantages over discrete solutions,” said Carsten Friedrich, Marketing Manager for Car Radio ICs at Atmel Corporation.
The antenna IC ensures crystal-clear reception without distortion even under extreme difficult and rapidly fluctuating field strength conditions typically found in moving antenna systems. In addition, board design can be extremely small and the ICs provide a rich set of features, including ESD protection.
I scanned the data sheet, and it says,
AM means long wave (LW), medium wave (MW) and short wave (SW) frequency bands (150 kHz to 30 MHz) that are usually used for AM as well as for DRM transmissions, and FM means any of the world wide used frequency bands for FM radio broadcast (70 MHz to 110 MHz).
Sooooo, some enterprising ham could probably design an active receiving antenna for the shortwave bands around this chip.