Maxtena provides advanced passive and active antennas for unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs).
These antennas play a crucial role in modern communication systems, acting as key components for transmitting and receiving electromagnetic waves.
Selecting the right antenna is essential for achieving optimal performance in any communication system. An antenna must effectively transmit or capture signals to reduce power loss and maintain efficiency.
Active Antennas
Active antennas feature a built-in Low Noise Amplifier (LNA) that strengthens weak incoming signals. The LNA operates using an external power source, such as a DC supply or battery, and is vital for increasing signal gain while reducing noise, particularly in low-signal conditions.
By amplifying weak signals before they reach the receiver, active antennas enhance overall system performance, making them indispensable for long-range communication, satellite systems, and environments where signal attenuation is a concern.
The integration of an LNA provides active antennas with greater sensitivity and improved signal-to-noise ratios, ensuring consistent reception in demanding conditions.
Maxtena active antennas are recognized for their high gain and low noise characteristics, making them suitable for UAVs, UGVs, IoT, smart cities, asset tracking, and automotive applications.
The M10HCT-A-TNC active GNSS antenna delivers up to 35 dB of gain with a noise figure of 1.3 dB, ensuring stable communication even in areas with weak signal coverage.
Passive Antennas
Passive antennas are widely used in various applications, such as television and radio systems, due to their straightforward design and effectiveness in environments with adequate signal strength.
These antennas do not require an external power source, instead capturing electromagnetic waves from the surrounding environment and converting them into electrical signals for use by connected devices. Their simple construction makes passive antennas cost-effective and efficient for applications where signal amplification is unnecessary.
Maxtena provides a diverse selection of passive antennas suitable for different applications. The M1575HCT-22P-SMA helical L1 passive GPS antenna is a reliable and durable choice for GPS applications. This antenna offers a gain of up to 22 dBi and a VSWR of 1.5:1, ensuring precise positioning and timing.
Comparison
The key difference between passive and active antennas lies in how they handle signal amplification. Passive antennas rely solely on capturing ambient electromagnetic waves, whereas active antennas include an LNA to amplify weak signals.
This amplification requires an external power source and enables active antennas to perform effectively in situations where signal levels are low, improving performance in long-range or weak-signal conditions.
Antennas in GNSS Applications
For Global Navigation Satellite System (GNSS) applications, an active antenna is generally the preferred choice over a passive antenna. The following factors explain why:
Weak Signal Amplification
GNSS satellites are positioned at significant distances (approximately 20,000 km from Earth), resulting in weak signals by the time they reach ground-based receivers.
Active antennas, featuring a Low Noise Amplifier (LNA), boost these weak signals before they reach the receiver, ensuring a stronger and more usable signal. In contrast, passive antennas rely entirely on capturing the signal, which may be too weak for effective processing.
Improved Signal-to-Noise Ratio (SNR)
The presence of an LNA in an active antenna enhances the signal-to-noise ratio (SNR) by amplifying the desired signal while reducing noise. For GNSS receivers, this leads to better performance, greater accuracy, and more dependable satellite tracking, which is critical for applications requiring precise positioning.
Compensation for Cable Length
In many GNSS installations, antennas are positioned at a distance from the receiver, such as on a vehicle roof or in an outdoor setting. With a passive antenna, long cable runs can lead to signal degradation. However, an active antenna counteracts this loss by amplifying the signal before it travels through the cable, reducing the impact of attenuation.
When a Passive Antenna May Be Suitable
A passive antenna can be a practical choice for GNSS applications under certain conditions:
- The signal strength is sufficient, such as in environments with minimal interference.
- The antenna is located near the receiver, reducing signal loss due to cable length.
However, in most GNSS applications, particularly where signals are weak or cable distances are long, an active antenna is the more dependable and effective option for ensuring strong signal reception and accuracy.
