In this era, wireless communication is the thing that everyone is talking about. This area has become so relevant in such a way that almost every engineer wants to specialize in it. When we talk about wireless communication, it’s all about antennas and the role they play in converting electromagnetic waves into electrical signals and vice versa. To be precise, transmitting antennas are the ones that convert electrical signals into electromagnetic waves whereas receiving antennas do just the opposite. They convert electromagnetic waves into electrical signals. If you want to receive signals on your television, you will use a receiving antenna.
Antennas are classified into three main categories. These are:
- Omnidirectional– omnidirectional antennas can receive signals from any direction. This means that you do not have to point them in any direction to receive signals. They are ideal to use in both urban and suburban areas.
- Semi-directional– semi-directional antennas are designed to receive signals from a particularly large area usually defined by an angle. For instance, depending on the area a semi-directional antenna can receive signals between 60 and 90 degrees. Any other position is known as “out of range” and no signals will be received.
- Highly-directional– highly-directional antennas just as the name suggests are very specific to the direction. You have to point them in a particular direction for them to receive the signal. They are used to link two distant points.
In this article, you will discover the most common types of antennas according to the TV antenna Sunshine Coast and how to point them. All these antennas fall under the three categories above.
- Directional Antennas
Both semi-directional and highly directional antennas fall under Directional antennas. The difference is that highly-directional antennas are more specific to direction than the semi-directional antennas. For these antennas, characteristics such as gain and impedance are similar for both the transmitting and the receiving antennas. What this means is that you can use the same antenna to send or receive signals. For a highly directional antenna, the gain is used to amplify a weak signal. This is what makes it best suited for long-distance transmissions.
- Patch Antennas
Also referred to as a “microstrip antenna” a patch antenna is a semi-directional radiator that uses a flat strip of metal and is mounted above a ground plane. The ground plane effectively cuts off the radiation from the antenna. This enhances the forward directionality of the radiation. These antennas have a beamwidth of 30-180 degrees and a gain of 9 dB.
- Yagi Antennas
Also Yagi-Uda array, yagi antenna is the most common type of directional antenna. It was invented in 1926 by Shintaro Uda and Hidetsugu Yagi, his colleague. A yagi antenna consists of several elements to create a directional array. These are:
- Multiple half-wave elements
- A single-driven element
- Multiple parasitic elements
- Parabolic Antennas
Also known as “dish antennas” parabolic antennas are also among the most common types of antennas. Parabola is the term used to describe a symmetric curve. And a parabolic reflector describes a 360 degrees curve. Because of its high degree of directivity, a parabolic reflector has the potential to take RF energy and focus it into a beam. Parabolic antennas are characterized by a narrow beamwidth usually 25 degrees and below. Their gain is dependent on the diameter of the antenna. For instance, at 2.4 GHz a 10-meter dish will provide a gain of 46 dBi while that of 1 meter will provide a gain of 26dBi.
Parabolic antennas are ideal to use for long-distance transmissions. The very large parabolic antennas are extensively used for radio astronomy. This is because they can provide a 10 million gain or approximately 70dBi.
- Grid Antennas
Grid antennas are a variation of the parabolic antenna. Since the parabolic antenna is made up of a large solid surface, a high or moderate can cause the dish to move or deform. A grid antenna is designed to prevent this from happening. The spacing between the grid elements depends on the frequency of the transmission. To be precise, the spacing is inversely proportional to the frequency of the transmission. This means that the higher the frequency, the smaller the spacing. And the lower the frequency, the bigger the spacing.
- Indoor vs outdoor Antennas
It’s impossible to talk about antennas without mentioning outdoor and internal antennas. Apart from the three categories above, all antennas are either indoor or outdoor. Indoor antennas are installed inside the house whereas outdoor antennas are placed outside the house.
Conclusion
In this digital era, you need an antenna for you to enjoy watching your favorite shows. That is why you need to understand the basics of how antennas work. The fact is, antenna directions is one of the most important things you need to know before you buy a TV antenna. Another important thing to understand is your location. You will need to buy an antenna that is best suited for your location for you to enjoy your TV entertainment to the fullest.
