LOS ANGELES � In-car reception is of vital importance to radio broadcasters. Competition for the ears of drivers has evolved from 8-track tapes, to cassettes, to CDs; now, easy access to the internet has generated an entirely new set of competitive challenges. These new technologies are challenging automotive radio vendors to improve radio reception while meeting different sets of requirements and cost targets, according to a recent article in eetimes.com. Let�s take a look at some of them and their solutions.
credit: Silicon Labs
Modern car radios look quite different from radios deployed in cars even ten years ago. Changes in antennas, displays, in-vehicle networks and new digital radio standards have made car radios much more versatile, but have also given rise to a suite of new challenges for car radio vendors.
Location in the dash. The entire radio system in legacy designs was in the center of the dash by the driver, with dedicated cables running from the antenna to the radio and from the radio to the speakers� amplifiers. Now, many designs use the center dash as a control center, communicating with the radio system placed elsewhere, such as in the vehicle trunk, often in a location that is closer to the car�s antennas. Closer location to radio antennas reduces cabling costs and the vehicle�s weight, which consequently can help improve the vehicle�s mileage, according to the same article.
Audio-video network. Many cars now feature audio-video networks, such as Media-Oriented Systems Transport or Ethernet AVB. The audio-video network runs around the inside of the vehicle, and enables each audio system to be placed in an optimal location. Instead of running dedicated cables between the different audio systems, each audio system � such as radio or audio amplifiers � is connected to the network and can transmit or receive data to other audio systems over the network.
credit: Silicon Labs
Embedded radio antennas. The most crucial element to good reception is the quality of the antenna and its location. Not surprisingly most manufacturers opt for appearance over performance. According to the same article, most modern cars embed radio antennas in the rear glass, side mirrors or a small �shark fin� structure placed on the car�s roof. �Modern antennas enable a cleaner look for the vehicle, but introduce new challenges for good radio reception as these antennas come with low antenna gain.� To improve FM reception, including reception challenges caused by embedded antennas, some car models deploy a secondary radio antenna � typically placed in a different location and pointing in a different direction from the primary radio antenna. In some ways this will compensate for poor the directionality of an embedded antenna, and perhaps even allows better reception in the opposite polarity.