Antenna design

From prototype development to series production, RF frontend accompanies your antenna application. RF-Frontend also supports the development of the front-end or the complete electronics up to the software.

Nowdays, many different antennas can be purchased for different radio standards. Whether external or integrated antennas, after connecting or installing the antenna in the device, quite often the antenna does not show the wantend performance. This is usually caused by the interaction of the antenna with the environment, e.g. the electronic circuit or the housing. The antenna specifications listed in the data sheets are often only valid for certain installation situations or environmental conditions, such as the free space.

In systems employing multiple antennas, e.g. MIMO or beamforming (Smart Antennas), in addition to the characteristics of the single antenna, the coupling of the antennas with each other is important. For a MIMO antenna system the decoupling (decorrelation) of the antenna elements is a precondition for the following algorithms.

Much of the problems described can be solved with numerical simulations. At RF Frontend we use the professional 3D EM simulator CST Microwave Studio, with which even very complex structures can be characterized.

RFID / NFC

RFID/NFC applications are ubiquitous in the modern daily life: in contactless payment and door locking systems, in electronic vehivle immobilizers or electronic passports, to name just a few examples. NFC transceiver chips are integrated in today's smart phones, which, among others, allow access to the ISO/IEC 14443 infrastructure. NFC devices can thus act as transponders or readers. In addition, NFC devices can communicate in the so-called peer-to-peer mode, which allows data to be exchanged between devices or establishes communication at a higher data rate with other radio standards such as Blutooth or WIFI.

Setup for ENVCo Precompliance Measurement
Setup for ENVCo Precompliance Measurement

The implementation of an RFID or NFC application becomes a challenge when particularly strict specifications have to be met or tough environmental conditions exist. An example is the EMVCo standard for contactless card payment transactions. EMV stands for Europay, Mastercard and Visa, the original companies that developed this standard. Today, this standard is maintained by the EMVCo consortium. EMV is a technical standard for payment cards and terminals. This standard defines the test equipment and test methods based on the ISO/IEC 14443 standard. If the reader coils are small or there are metal parts near the reader coil, special transceiver chips and additional amplifiers are often required to meet the specifications. In addition to the magnetic field strengths, the specifications for the modulation parameters must also be met. Field strength and modulation parameters depend mainly on the front-end of the designed reader.

RFID coil for operation on a metal surface (ENVCo Level 1)
RFID coil for operation on a metal surface (ENVCo Level 1)

As an expert in high frequency circuits and communication systems, RF-Frontend supports you in realizing your RFID/NFC applications for all common RFID standards:

  • LF (125 kHz, 134 kHz)
  • HF (ISO/IEC 15693, ISO/IEC 14443, EMVCo, ISO/IEC 18000-3, ISO/IEC 18092 NFC, ISO/IEC 21481 NFC)
  • UHF (EPCglobal Gen 2, ISO/IEC 18000-6c)

UHF reader antennas

Miniaturized, circular polarized UHF antenna for RFID readers
Miniaturized, circular polarized UHF antenna for RFID readers

Circularly polarized UHF reader antennas play an important role in RFID applications. Usually, they require small reader housings, strict specifications regarding input impedance matching, bandwidth (886 MHz and 922 MHz band), antenna gain, half power bandwidth (HPBW) and axial ratio. Commercially available antennas rarely meet most of the required specifications, therefore, a custom solution must be realized. For that, RF-Frontend is the right contact for you!

WiFi Antennas

Dual-band WLAN PCB Antenna
Dual-band WLAN PCB Antenna

WLAN applications are omnipresent in our daily lives. Whether smartphone, smart TV or sensors, communication with these devices takes place via WLAN. Here the antenna plays a central role for good communication with the router.

Dual-band WLAN PCB Dipole Antenna
Dual-band WLAN PCB Dipole Antenna

RF-Frontend offers the right antenna solutions for both high-end devices and low cost applications.

Broadband antennas

Logarithmic periodic PCB antenna 600MHz-8GHz (Gain: 5dBi)
Logarithmic periodic PCB antenna 600MHz-8GHz (Gain: 5dBi)

In antenna measurement technology and for the reception of signals in broadband radio standards, such as DVBT (470 MHz to 870 MHz), so-called broadband antennas with relatively constant parameters (e.g. input impedance, antenna gain) are required. Depending on the desired directional characteristic (omni-directional or directional antenna), the frequency range and the manufacturing costs, RF-Frontend offers customized antenna designs.

Matching measurement of the log-periodic PCB antenna 600MHz-8GHz
Matching measurement of the log-periodic PCB antenna 600MHz-8GHz

Good matching in the range 600MHz to 8.5GHz.

Antenna arrays

Series-fed antenna array of a radar module
Series-fed antenna array of a radar module

Antenna arrays are used to increase the antenna's directivity or to electronically control the main radiation beam. Due to factors like antenna coupling (radiation coupling) and radiation, as well as the losses of the distribution network, the design of an antenna array is a special challenge. Here RF-Frontend has a particularly good expertise thanks to many years of experience.

Distribution network, 2.4GHz and 5GHz WLAN antenna array
Distribution network, 2.4GHz and 5GHz WLAN antenna array

The photo on the left shows a section of a distribution network for a linear 16-element antenna array (2.4 GHz and 5 GHz WLAN band). The broadband Wilkinson couplers can be seen very clearly.