The Benefits of BEC s Antenna Design

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The Benefits of BEC s Antenna Design Overview The explosive growth of wireless data communications is fast emerging with high peak data rates, which require superior antenna performance and design to

A critical component, the antenna radiates and receives the RF or microwave power. It is a reciprocal device, and the same antenna can serve as a receiving or transmitting device.

Guided waves are confined to the boundaries of a transmission line to transport signals from one point to another, while free-space waves radiate unbounded.

occurs due to discontinuities (which cause the perturbation of fields or currents), unbalanced currents, and so on.

1 The Benefits of BEC s Antenna Design Overview The explosive growth of wireless data communications is fast emerging with high peak data rates, which require superior antenna performance and design to support the bandwidth requirements. Also the increasing expectations for speed, bandwidth and global access by consumers is driving the evolution of wireless broadband technology. A critical component, the antenna radiates and receives the RF or microwave power. It is a reciprocal device, and the same antenna can serve as a receiving or transmitting device. Antennas are structures that provide transitions between guided and free-space waves. Guided waves are confined to the boundaries of a transmission line to transport signals from one point to another, while free-space waves radiate unbounded. A transmission line is designed to have verylittle radiation loss, while the antenna is designed to have maximum radiation. The radiation. occurs due to discontinuities (which cause the perturbation of fields or currents), unbalanced currents, and so on. [1] BEC offers a series of 4G LTE antennas for both our indoor and outdoor product solutions. These antennas all support MMO and come in multiple form factors: Dipole, Omni, Panel and Patch. Analysis with the Performance Similar to copper technologies such as DSL, LTE fixed wireless service availabilities are limited by its distance, or signal coverage. Although selecting the right tower antenna and conducting a thorough propagation could help increase the coverage. Selecting a high performance & reliable CPE product is essential to improve user experience and service quality. Through the use of MIMO technology and BEC s unique SX antenna technology, the range of a LTE fixed wireless broadband network can be greatly increase by up to 40% reducing the number of enodeb base stations required for maximum coverage. Antenna design is the major component of any wireless system. In LTE systems, the commonly used antennas are dipoles, omnidirectional antennas, patch and Yagi. Examples of each antenna are shown in Figure 1. (a) (b) (c) (d) Figure 1. (a) BEC Dipole Antenna; (b) BEC Omnidirectional Antenna; (c) BEC Patch Antenna; (d) BEC Yagi Antenna

2 Basic Definitions The antenna and antenna terminology is often defined as a transmitting antenna and receiving antenna. The typical wireless system is show in figure 2. Figure 2. Typical Wireless System An antenna is a transducer between a guided wave and a radiated wave, or vice versa. The structure that "guides" the energy to the antenna is most evident as a coaxial cable attached to the antenna. The radiated energy is characterized by the antenna's radiation pattern. Antenna Pattern (a) (b) Figure 3. Antenna analysis: (a) spherical coordinates; (b) antenna and observation point The radiation pattern (antenna pattern) is the graphical representation of the radiation properties of the antenna as a function of space. Also the antenna's pattern use to describe how the antenna radiates energy transmits or receives into space. Figure 3 shows a possible coordinate system used for making such antenna measurements. Lobes Any given antenna pattern has portions of the pattern that are called lobes. The sidelobes are power radiation peaks in addition to the main lobe. The sidelobe levels (SLLs) are normally given as the number of decibels below the main-lobe peak. In general, a lobe is any part of the pattern that is surrounded by regions of relatively weaker radiation. Figure 4 shows the radiation pattern with the lobes labeled.

antenna to radiate the energy presented to its terminal: Where Pradis the actual power radiated, Pin is the power coupled into the antenna, and Ploss is the power lost in the antenna.

3 (a) (b) Figure 4. Radiation Patterns in Polar and Cartesian Coordinates Showing Various Types of Lobes Gain [1] The gain of an antenna is the directivity multiplied by the illumination or aperture efficiency of the antenna to radiate the energy presented to its terminal: Where Pradis the actual power radiated, Pin is the power coupled into the antenna, and Ploss is the power lost in the antenna. The losses could include ohmic orconductor loss, dielectric loss, and so on. In general, the narrower the beamwidth, the higher the gain. Figure 5 gives a comparison of gain for three different antennas. Figure 5. Gain comparison Beamwidth The half-power beamwidth (HPBW) or 3-dB beamwidth is the range in degrees such that the radiation drops to one-half of (or 3 db below) its maximum.[1] Antennas with wide beamwidths typically have low gain and antennas with narrow beam widths tend to have higher gain. Remember that gain is a measure of how much of the power is radiated in a given direction. So an antenna that directs most of its energy into a narrow beam (at least in one plane) will have a higher gain. [2] Input VSWR and Input Impedance As the one-port circuit, an antenna is described by a single scattering parameter S11or the reflection coefficient Γ, which gives the reflected signal and quantifies the impedance mismatch between the source and the antenna [1]

4 1. Indoor Antenna In radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna. It consists of two identical conductive elements such as metal wires or rods, which are usually bilaterally symmetrical. The driving current from the transmitter is applied, or for receiving antennas the output signal to the receiver is taken, between the two halves of the antenna. Each side of the feedline to the transmitter or receiver is connected to one of the conductors. This contrasts with a monopole antenna, which consists of a single rod or conductor with one side of the feedline connected to it, and the other side connected to some type of ground. A common example of a dipole is the "rabbit ears" television antenna found on broadcast television sets. Theoretically, an optimal MIMO antenna performance can be achieved when data channels are uncorrelated to each other. However, due to multi-path fading along the propagation channel and correlation between the antennas it is unlikely that channel correlations can be avoided. In a fixed wireless scenario, the slower variation of radio channel enables more accurate adaptation of transmission parameters. By leveraging this advantage, BEC s SX Antenna Technology uses adaptive signal processing techniques to compensate such an impairment, improving the gain level and distribution range, thus enabling the maximum benefits of a MIMO performance. The BEC indoor antennas (Dipole) are designed for the 6200WZL and 6300VNL Series of 4G LTE Broadband Routers. These antennas have good performance of frequency range, high gain, VSWR ratio and high isolation. The following table displays the antenna specifications in greater detail. Name Frequency (MHz) SWR Band Antenna Gain Polarization SX-7 700~960 Band Linear 1710~ ± Band SX ~ 960 MHz 1710 ~ 2170 MHz Table 1.1 BEC Indoor Antenna Specifications <=3.5: 700~960MHz <=4.0: 1710~2700MHz <=2.0@880 MHz <=3.0@1880MHz 2/3/7/8/4/12/13 /14/17/20/25/3 8/39/40/41 2/3/4/25 2.0± 0.5dBi@ 824 ~ 960 MHz 1.0±0.5dBi@1710~2170 MHz Linear SX ~ 2700 MHz <= 2.5 7/38/41 6dBi Linear 2. Outdoor Antenna An outdoor antenna not only needs good RF performance it requires reliable operation in harsh outdoor environments. BEC outdoor antennas offer superior range and coverage across multiple form factors such as embedded directional panel or Omni-directional detachable antennas. Key features of BEC outdoor antennas include: Support for most North America and Global LTE bands Optimized single band and multi-band designs Patented Dual-Pol dual polarization antenna technology for faster and efficient bi-directional transmission High isolation for stable and reliable connections Precise alignment achievable with multi-angel, multi-position pole mount brackets The following table displays the antenna specifications in greater detail. Table 2.1 BEC Outdoor Antenna Specifications Name Frequency (MHz) SWR Band Antenna Gain Omni 700MHz Omni 1700MHz MHz 2.0 typ., 2.5 max MHz 2.0 typ., 2.5 max. 12/13/14/17/20 5dBi Linear, Vertical 2/3/4/39 9dBi Linear, Vertical Polarization BW/Azimuth BW/Elevation Max. Power Input W W

5 Table 2.1 BEC Outdoor Antenna Specifications (Cont.) Name Frequency (MHz) SWR Band Antenna Gain(dBi) Polarization LTE 690~798 <2.0:1max. 12/13/14/17 5.5~7 Vertical, B12B13B14B17 Horizontal DP Antenna LTE B3B4 DP 1710 ~ 2170MHz <2.0:1max. 2/3/4 9~10.5 Vertical, Antenna Horizontal LTE B3B4 DP 1710 ~ 2170MHz <1.9:1max. 2/3/4 8~10 Vertical, Antenna LTE B41 DP Antenna(TDD) Horizontal 2496~2690MHz 1.8max: ~16.5 Dual Pol. (Vertical / Horizontal) H-plane HPBW V-plane HPBW 74: 70 69; 75 55~80: 35~50: 35~50 55~80 60~70; 40~55; 40~55 60~70 22; 21 23; 22 Figure 6. Omni 700MHz Pattern (a) Radiation Patterns of Port#1

6 (a) Radiation Patterns of Port#1 (b) Radiation Patterns of Port#1 Figure 7. LTE B12B13B14B17 DP Antenna Radiation Patterns In some cases where existing cellular single is low YAGI directional antennas are a great option for indoor LTE devices such as the 6200WZL and 6300VNL Series of 4G LTE Broadband Routers. Yagi antennas are designed to only send and receive from a single direction, they are able to transmit a much stronger signal than omnidirectional antennas and can also receive weaker signals. Table 2.2 BEC Yagi Antenna design Name Frequency(MHz) SWR Band Antenna Gain YAGI 13dBi YAGI 15dBi Polarization Beam width deg Max. Power Input MHz <=1.7 12/13/14/17 13dBi Vertical Horz.47 Vert W MHz <=1.5 2/3/4 15dBi Vertical Horz.28 Vert W

Kai Chang Copyright#2000 John Wiley & Sons, Inc.

7 The following graphs show some Yagi antenna s performance Figure 9. Radiation Patterns of Yagi 13dB Figure 10. Radiation Patterns of Yagi 15dB References [1] RF and Microwave Wireless Systems. Kai Chang Copyright#2000 John Wiley & Sons, Inc. ISBNs: (Hardback); (Electronic) [2] Antenna Patterns and Their Meaning (Cisco White Paper: 06a1a3e.html)

Antenna Fundamentals Basics antenna theory and concepts

Antenna Fundamentals Basics antenna theory and concepts M. Haridim Brno University of Technology, Brno February 2017 1 Topics What is antenna Antenna types Antenna parameters: radiation pattern, directivity,