Antenna PCB

An antenna PCB is a printed circuit board specifically designed for RF signal radiation, reception, transmission, or antenna module integration. Unlike standard signal PCBs, antenna PCBs require strict control over the dielectric constant (Dk), copper foil pattern geometry, and surface finish to maintain a consistent radiation pattern and resonant frequency. Even a deviation of ±0.1 in the Dk value can cause measurable frequency drift in patch antenna designs. Common antenna PCB types include patch antennas, slot antennas, dipole antennas, MIMO arrays, and phased array modules, widely used in WiFi, 5G, GPS, radar, and satellite communications.

Antenna PCBs operate from low frequencies (below 1 GHz) to millimeter-wave frequencies (above 30 GHz). Common applications include RFID (125 kHz - 2.45 GHz), ISM bands (433 MHz, 868 MHz, 915 MHz), WiFi (2.4 GHz, 5 GHz), cellular networks (700 MHz - 6 GHz), GPS (1.575 GHz), and 5G millimeter wave (24-39 GHz).

The gain of a PCB antenna varies depending on the type and design. Patch antennas typically achieve a gain of 3-9 dBi, monopole antennas around 2-3 dBi, IFA designs around 2-5 dBi, while array configurations can achieve higher gains, up to 15 dBi or higher. The actual gain depends on the substrate characteristics, antenna size, and ground plane configuration.

Materials with lower dielectric constants and loss tangents reduce signal loss, thus providing better RF performance. Common materials for enhancing RF performance include Rogers, Teflon, and FR4.

The antenna trace impedance is 50 ohms, and other RF components in the design (such as radio modules) should also be set to 50 ohms. The transmission lines that carry RF energy to and from the antenna are a critical factor determining wireless performance.

All antenna PCB projects include an engineering review before production. We review whether the materials are suitable for the operating frequency, the stack-up structure, the dielectric layer thickness between the antenna layer and the ground layer, the copper layer thickness, the impedance design, the trace width calculation, and the production feasibility. For multilayer antenna PCBs using a hybrid stack-up, we also review material compatibility and lamination order. When requesting a review, please provide Gerber files, a stack-up diagram, the operating frequency, and impedance requirements.

The minimum trace width and spacing for advanced products is 2.5mil/3mil, and for standard products it is 3mil/4mil. Trace width tolerance is ±0.01mm. For antenna PCB design, the feed width is calculated based on the substrate dielectric constant (Dk), dielectric thickness, and target impedance. We can verify your trace width calculations during the pre-production engineering review phase to ensure the final manufactured board matches your impedance design.

The antenna resonant frequency directly depends on the electrical length of the antenna element, which in turn depends on the substrate dielectric constant (Dk). If the substrate dielectric constant varies between batches or even between different batches, the antenna resonant frequency will shift, and the radiation pattern will degrade. For a 5GHz patch antenna, a change in dielectric constant of ±0.1mm can cause a frequency shift of approximately 100-150MHz, enough to cause the antenna to exceed its intended frequency band. For antenna PCB projects with high frequency accuracy requirements, we use materials with strict dielectric constant tolerances, such as Taconic TLY-5 (dielectric constant 2.22±0.02) and Rogers RO4350B (dielectric constant 3.48±0.05).

Please prepare the following information: Gerber file (ZIP format), material requirements (e.g., Rogers RO4350B 0.508mm), PCB stack-up structure, board thickness, copper foil thickness, surface treatment, quantity, operating frequency, and impedance requirements. For antenna PCBs, please also provide the dielectric layer thickness between the antenna layer and the ground layer, as this directly affects the impedance and antenna resonant frequency. After the initial contact, you can send the Gerber file via WhatsApp or email.