George Hardesty

May 122018

Zigbee is a low-cost wireless technology used for short-range, low-power radio communication. ZigBee devices are almost exclusively limited to low bandwidth (1MHz) personal area networks.

Most commercial ZigBee devices operate at 2.4GHz, although some devices run on other ISM bands such as 900MHz and 868 MHz frequency bands. ZigBee has a data transmission rate of 250 Kbit/s, and a maximum range 10 – 30 meters at a power consumption rating of 1mW at low and 100mW at peak.
The low power consumption, low data rates, and short range make ZigBee ideal for use in low power communication devices in close proximity. ZigBee can be integrated into a mesh network for long-range data transfers.
XBee is a radio communication device developed by Digi International for low power point-to-point and star transmission; suitable for ZigBee technology. It consists of a 20-pin through-hole-mount interface or 38-pad surface mount, and a U.FL jack or RP-SMA antenna. Variations in power consumption, RF frequency, and antenna type depend on the various brands of the product.
Zigbee is commonly used in mesh networks and in low power battery powered devices. Its low cost for transmission makes it ideal for IoT (Internet of Things) devices, especially in close range. Other Popular applications of ZigBee include:
  • Building automation
  • Energy management systems
  • Home entertainment systems
  • Remote controls
  • Traffic management systems
Apr 272018

ISM means Industrial, Scientific and Medical frequency band. This is a band of radio and microwave frequencies clustered around 2.4GHz, reserved and designated for industrial, scientific and medical equipment that use RF. Industrial equipment like MRI machines, testing equipment, and some radio telescopes use this ISM band of frequencies. Smaller consumer devices such as microwave ovens, garage door system, codeless phone, wireless router and wireless mouse are also designed to run at frequencies around 2.4 GHz.

Most telecommunication devices operate at a much lower frequency than 2.4GHz. Having other devices operate at only a certain frequency range, in this case, ISM, reduces interference with the telecommunication frequencies. This means that using a wireless router and a cellular phone at the time will have no interference with each other.

2.4GHz is not the only ISM frequency. It is only the most common because there is no need for licensing devices to use it. Other ISM frequencies can be as high as 24.125GHz or even as low as 13.56MHz. Depending on the location and local acceptance, authorities can allocate ISM radio frequencies with some little flexibility.

Allocation of ISM radio frequencies is stipulated by the International Telecommunication Union (ITU). ITU has documented a worldwide ISM allocation table which varies slightly depending on the region. ISM users must accept laid down terms and regulations to ensure safety and avoid interference.

Apr 272018

IoT (Internet of Things) is a network of physical devices each able to communicate with the other using the existing internet channel. The devices “Things” are common everyday devices and equipment, including smartphones, wearables, vehicles, and instruments.

Each device in the network is uniquely identifiable and able to exchange data with over devices over IP. Devices are embedded with software and connectivity features to enable this communication.

IoT devices have a flexible range of both wired and wireless connectivity options. Wireless connectivity medium can be categorized into short-range, medium-range and long-range. Short-range connectivity is most common, IoT devices rarely need to connect to long-range.

Wired IoT devices use Ethernet, coaxial or power communication cables.

Short-range:  This includes connectivity methods that use ISM band frequencies of 4.33GHz, 5GHz, and 2.4Ghz. Such as:

  • Bluetooth
  • Light Fidelity (Li-Fi)
  • Near field communication
  • QR codes and barcodes
  • RFID
  • Wi-Fi
  • Wi-Fi direct
  • Z Wave
  • ZigBee

Medium-range:  For medium range, the LTE Advanced network is almost exclusively preferred for its low latency, high data rates, and extended range. Mid-range variants of Wi-Fi such as HaLow are also used.

Long-range:  LPWAN (Low-power wide-area networking), though it transmits at low data rates, LPWAN is ideal for long distance IoT transmissions for its economic power consumption and cost of transmission.

Long-range satellites such as VSAT transmitting narrowband and broadband are also used.

IoT is quickly gaining popularity in several businesses, commercial, and industrial fields. With time we expect to see standards and improved connectivity of IoT Things.

Apr 272018

The IEEE 802.11ac is a wireless Wi-Fi standard developed within 2008-2013 to provide high-throughput connectivity across the 5GHZ band. The standard is an improvement on the earlier 802.11n wireless standard transmitting via the 2.4GHz frequency band.

Key advantages of 802.11ac over 802.11n
  • 802.11ac has a combined multiple-station throughput of at least 1Gbs and a singular throughput of at least 500Mbs through a single link. 802.11ac features a wider bandwidth of 160MHz, up to 8 MIMO special streams, higher density modulation of 256 QAM, and up to 4 simultaneous downlink users.
  • 802.11ac also introduces standardized beamforming transmission technology. Beamforming transmits only the required signal to the specific user. This makes transmission more efficient, consistent and saves on the power cost of transmission.
  • 802.11n can only support a 4X40MHz bandwidth compared to 802.11ac’s 8X160Mhz. the high-density modulation allows 256 different signals to be transmitted over the same frequency by phase shifting each signal; this improves the spectral efficiency up to 4 times over 802.11n.
  • Another great advantage 802.11ac has over the 802.11n is the use of the 5GHz band of frequency. 802.11n runs on the heavily overused 2.4Ghz which is prone to interference from the many devices on this spectrum. Although it has less penetrating power, the 5GHz band is free from high noise and congestion. A quality Wi-Fi antenna fitted to a 5GHz router improves its range within usable distances.
Despite the significant differences between the two standards, 802.11ac is fully backward compatible with 802.11n. devices that feature a dual frequency receiver can easily switch between the two standards.
Apr 012018


LTE (4G), GSM (3G & 2G), CDMA (3G & 2G), and ISM. The fundamental differences between these four modern technologies is the way they transmit and receive information.

LTE (Long Term Evolution) is a 4G communication standard designed to be 10x faster than standard 3G. the technology provides IP-Based communication of voice and multimedia and streaming at between 100 Mbit per sec and 1 Gbit per second. LTE has an algorithm that is able to send large chunks of data via IP. This approach streamlines the traffic and reduces latency.

GSM is an abbreviation for Global System for Mobile Communication. GSM is a digital cellular technology used to transmit data and voice communication at a frequency range of 850MHz to 1900MHz. GSM technology uses a Time Division Multiple Access (TDMA) technique to transmit data. The GSM system converts the data into a digital signal and sends it through two different time stamped channels at a rate between 64 kbps and 120 kbps.

CDMA stands for Code Division Multiple Access. CDMA uses a multiple access mode of communication. This is where several transmissions are made over the same channel simultaneously. Using a speed spectrum, each transmission is assigned a unique code that corresponds to the source and destination of the signal.

ISM:  industrial, scientific and medical radio bands reserved for medical, scientific and industrial use and not intended for telecommunication. Originally this band of radio frequencies was intended for use in industrial, scientific and medical ISM machines that operate at this range in order not to interfere with the wider
Mar 212018

1. Please give us the spec of the IP camera.

2. Please check if the IP camera supports standard PoE(802.3at/af) or passive PoE.?

3. if it supports standard PoE, it needs to use the 48V power adapter (Note: need to check the power pin of the RJ-45 is Pin4,5,7,8 or 1,2,3,6; our APOE03 use the pin4,5,7,8)

4. If it supports passive PoE, it needs to check the power pin of the RJ-45 is Pin 4,5,7,8 or 1,2,3,6.  our APOE03 uses the pin 4,5,7,8.

If the IP camera is IEEE802.3 af/at standard   PoE:  Use a 48V power supply + APOE03 .  A 48V power supply must with a standard DC barrel connector is the best option, for ease of installation.

Feb 172017

Example:  You need only 860-960 MHz GSM band but the antenna covers 800-960MHz:  One customer told us that using an antenna that includes 824-960 band allows too much interference, that comes from the low end of that band 824-860MHz.

Our recommended  solution is to add a filter in your system board (or AP board), and thereby enable use of an antenna that covers a wider band, such as 800-960MHz or 824-960MHz, as examples:  Because you will find many more antenna options that cover 800-960MHz or 824-960MHz than just 860-960MHz.

800-860MHz is a very close band to 860-960MHz frequency band and the antenna is a passive device which can’t filter; therefor, you need to have an active circuit to filter 800-860MHz frequency.

 Posted by at 9:17 am Antennas Tagged with:  No Responses »
Feb 122017
1 1920 – 1980 2110 – 2170
2 1850 – 1910 1930 – 1990
3 1710 – 1785 1805 – 1880
4 1710 – 1755 2110 – 2155
5 824 – 849 869 – 894
6 830 – 840 875 – 885
7 2500 – 2570 2620 – 2690
(GSM) 880 – 915 925 – 960
9 1749.9 – 1784.9 1844.9 – 1879.9
10 1710 – 1770 2110 – 2170
11 1427.9 – 1452.9 1475.9 – 1500.9
12 698 – 716 728 – 746
13 777 – 787 746 – 756
14 788 – 798 758 – 768
15 1900 – 1920 2600 – 2620
16 2010 – 2025 2585 – 2600
17 704 – 716 734 – 746
18 815 – 830 860 – 875
19 830 – 845 875 – 890
20 832 – 862 791 – 821
21 1447.9 – 1462.9 1495.5 – 1510.9
22 3410 – 3500 3510 – 3600
23 2000 – 2020 2180 – 2200
24 1625.5 – 1660.5 1525 – 1559
25 1850 -1915 1930 – 1995
26 814 – 849 859 – 894
27 807 – 824 852 – 869
28 703 – 748 758 – 803
29 n/a 717 – 728
30 2305 – 2315 2350 – 2360
31 452.5 – 457.5 462.5 – 467.5
33 1900 – 1920
34 2010 – 2025
35 1850 – 1910
36 1930 – 1990
37 1910 – 1930
38 2570 – 2620
39 1880 – 1920
40 2300 – 2400
41 2496 – 2690
42 3400 – 3600
43 3600 – 3800
44 703 – 803
Oct 092016

We offer two options of thickness of cable for U.FL cables:

1.13mm mini-coaxial cable (50 Ohm): This is a very thin and flexible cable, with a black jacket. When connecting U.FL connector to a jack on a miniPCI card or board, sometimes the tight space requires the use of 1.13mm cable, because it is very thin and flexible: It is not always necessary to use 1.13mm cable, but on occasion it is necessary to use 1.13mm cable, to prevent the U.FL connector from popping off the U.FL jack.

LMR-100-equivalent cable-type: This is a low-loss coax option for U.FL but not for MHF4 or W.FL.   LMR100  cable is double-shielded, low-loss and very flexible/easily bendable coax with black jacket. The double-shielding is a major factor in the higher quality of this cable, which translates into lower loss/better performance. Has the same or better signal-loss-per-meter and flexibility as LMR100, and less attenuation (signal loss) than RG174 and RG178. The higher quality of the cable of this antenna translates into lower loss/better performance. Cable is equivalent to LMR-100 in thickness.   Since the LMR-100 equivalent coax has lower signal loss:  If this cable works for you without the U.FL connectors popping off the jacks, then the thicker one is the better solution.  You can use a hot glue gun to secure the jack onto the PCB, in which case, of course, the thicker cable will not be a problem:  This is the best way.

We can make special orders of U.FL cables with either LMR-100 equivalent (for lower signal loss) or 1.13mm cable, for better flexibility.

MHF4 cables, and W.FL cables cables can only be made with the very thin coaxes such as 1.13.   MHF4 is not compatible with LMR100 and RG178.


U.FL (Ultra-Miniature Coaxial Connector) is part of the UMCC (Ultra Miniature Coax Connectors) series by Hirose Electric Co Ltd. The U.FL series has become a standard in the wireless industry. It provides an extremely small mounting area weight. The series also offers high frequency performance and has a user friendly tactile lock feeling that ensures a reliable connection.

U.FL male right-angle connector mates with U.FL jack/cable-connector U.FL-LP-66, found on mini-PCI wireless cards such as: MikroTik, Ubiquiti, ZigBee radios such as XBee, and Intel PRO: This pigtail enables connection of an external antenna to a mini-PCI wireless card with a female HiRose/U.FL connector U.FL-LP-66 connector.

Data Alliance’s U.FL connectors are precision machined and gold-plated for low loss.

Lead-free and ROHS compliant: Our antenna cable products are ROHS compliant (connectors and cable).

Attenuation of 1.13 Coax for Microconnectors

Attenuation of 1.13 Coax for Microconnectors

UFL to SMA cable diagram

U.FL to SMA Cable diagram

UFL male and female connectors

If there is a U.FL jack on your PCB, it is a U.FL male.

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