Satellite dish

Lore & Background

Parabolic or 'dish' antennas had been in use as radio telescopes (beginning in 1937) and airplane tracking by the military (during WWII) long before the first artificial satellite was launched in 1957. The term satellite dish was coined in 1978 during the beginning of the satellite television industry, and came to refer to dish antennas that send and/or receive signals from communications satellites. Taylor Howard of San Andreas, California, adapted an ex-military dish in 1976 and became the first person to receive satellite television signals using it.

The first satellite television dishes were built to receive signals on the C-band analog, and were very large. The front cover of the 1979 Neiman-Marcus Christmas catalog featured the first home satellite TV stations on sale. The dishes were nearly 20 ft in diameter. The satellite dishes of the early 1980s were 10 to 16 ft in diameter and made of fiberglass with an embedded layer of wire mesh or aluminium foil, or solid aluminium or steel. Satellite dishes made of wire mesh first came out in the early 1980s, and were at first 10 ft in diameter. As front-end technology improved and the noise figure of the LNBs fell, the size shrank to 8 ft a few years later, and continued to get smaller reducing to 6 ft by the late 1980s and 4 ft by the early 1990s. In December 1988, Luxembourg's Astra 1A satellite began transmitting analog television signals on the Ku band for the European market, allowing small dishes (90 cm) to be used reliably for the first time. On 4 March 1996, EchoStar introduced Digital Sky Highway (Dish Network), the first widely used direct-broadcast satellite television system, allowing dishes as small as 20 inches (51 cm).

Reader's Guide

The satellite dish's significance lies in its transformation from a large, expensive C-band installation to a compact, affordable consumer product that enabled direct-broadcast satellite television. The reduction in dish size, driven by improvements in LNB noise figures and the shift to Ku-band transmissions, allowed dishes to be installed on vehicles and became ubiquitous for home television reception. Television stations, however, still prefer to transmit their signals on the C-band with large dishes due to the fact that C-band signals are less prone to rain fade than Ku band signals. The parabolic shape of a dish reflects the signal to the dish's focal point, where a feedhorn gathers the signals and conducts them to a low-noise block downconverter (LNB). Modern dishes intended for home television use are generally 43 cm to 80 cm in diameter and fixed in one position for Ku-band reception from one orbital position. The legacy of the satellite dish includes the development of motor-driven dishes, multi-satellite reception using multiple LNBs, and the integration of the feedhorn with the LNB (LNBF). A new form of omnidirectional satellite antenna, which does not use a directed parabolic dish and can be used on a mobile platform such as a vehicle, was announced by the University of Waterloo in 2004.

Did You Know?

• Taylor Howard of San Andreas, California, became the first person to receive satellite television signals using an adapted ex-military dish in 1976.
• The first home satellite TV stations appeared in the 1979 Neiman-Marcus Christmas catalog with dishes nearly 20 ft in diameter.
• EchoStar's Digital Sky Highway (Dish Network), introduced on 4 March 1996, was the first widely used direct-broadcast satellite television system, allowing dishes as small as 20 inches.

Origins and Early Adoption

Parabolic antennas predate artificial satellites by decades. As early as 1937, dish-shaped structures were employed as radio telescopes, and during World War II the military put them to work tracking aircraft. It was not until 1957 that the first artificial satellite entered orbit, yet the dish concept was already well established in radio science. The specific phrase 'satellite dish' did not enter common usage until 1978, when the satellite television industry was just taking shape. A pivotal moment came in 1976, when Taylor Howard of San Andreas, California, repurposed a decommissioned military dish and became the first individual to capture satellite television signals. By the 1979 Neiman-Marcus Christmas catalog, home satellite TV stations were being marketed to consumers, though the hardware was enormous—nearly 20 feet in diameter and tuned to the C-band analog spectrum. These early installations were far from the compact backyard units most people picture today.

How the Dish Actually Works

A common misconception holds that the small feedhorn assembly at the front of a dish grabs the signal straight out of the sky. In reality, the parabolic surface does the heavy lifting: it collects incoming radio waves over its broad face and reflects them to a single focal point. At that focal point sits a feedhorn, which acts as the entrance to a waveguide, channeling the concentrated energy to a low-noise block downconverter, or LNB. The LNB translates the electromagnetic signal into an electrical one and shifts the C-band or Ku-band frequency down into the L-band range. In direct-broadcast satellite setups, the feedhorn and LNB are merged into a single unit called an LNBF. Theoretical gain rises with frequency, though real-world performance depends on surface finish, shape accuracy, and feedhorn matching. A typical 60 cm consumer dish operating at 11.75 GHz achieves roughly 37.5 dB of directive gain.

The Shrinking Dish

The most visible transformation in satellite television history is the dramatic reduction in dish size. Early C-band dishes measured 10 to 16 feet across, constructed from fiberglass with embedded wire mesh or aluminium foil, or from solid aluminium and steel. As front-end electronics improved and LNB noise figures dropped, sizes fell to 8 feet, then 6 feet by the late 1980s, and 4 feet by the early 1990s. A true breakthrough arrived in December 1988, when Luxembourg's Astra 1A began broadcasting analog television on the Ku band for Europe, making reliable 90 cm dishes possible for the first time. In the early 1990s, four major American cable companies launched PrimeStar, a direct-broadcast service using medium-power satellites whose strong Ku-band signals again enabled 90 cm dishes. Then on 4 March 1996, EchoStar's Digital Sky Highway—later known as Dish Network—became the first widely adopted direct-broadcast satellite system, shrinking the required dish to just 20 inches. That compact size also made vehicle-mounted satellite reception practical, a capability that persists to this day.

Engineering the Home Installation

Behind the simple act of turning on a satellite TV lies a carefully engineered signal chain. In a typical single-receiver home setup, one coaxial cable runs from the set-top box to the LNB on the dish. That same cable carries DC power to the LNB, transmits the received signal back to the receiver, and conveys control signals. The receiver toggles between 13 and 18 volts to select vertical or horizontal polarization, and sends a 22 kHz pilot tone to tell the LNB which of two frequency bands to pass. In Europe, DBS services occupy 10.7 to 12.75 GHz, split into a low band (10.7–11.7 GHz) and a high band (11.7–12.75 GHz), each supporting both horizontal and vertical polarizations. The LNB downconverts these to 950–2150 MHz for transmission over the coaxial cable. Because only one of these four band-and-polarization combinations fits on a single coaxial line at a time, multi-receiver installations require a switching matrix or the receiver must select one combination at a time.