Printed Antenna Layout Generator

From an antenna specification to PCB copper

Printed antennas turn a frequency and a substrate into copper shapes. A patch antenna is a resonant cavity whose length is close to half a wavelength in the substrate; a printed dipole or monopole is a half or quarter wavelength of strip; a Yagi-Uda or log-periodic array is a row of such elements with carefully chosen lengths and spacings; a Vivaldi or spiral antenna is a broadband taper. This tool takes your frequency, permittivity, loss tangent and substrate height, applies the standard design equations for each type, and draws the structure to scale with every dimension labelled. The feed lines use the Hammerstad-Jensen microstrip model with the Kirschning-Jansen dispersion correction, the same engine used in the RF Passives PCB Layout Designer.

Which equations are used?

Rectangular patches follow the transmission-line model with the Hammerstad effective permittivity and length extension, and the edge resistance comes from the slot conductance integrals, which sets the inset depth or the probe position. Circular patches use the cavity model with the usual fringing correction. Dipole, monopole, bow-tie, inverted-F, meander and slot lengths are quarter or half wavelengths reduced by the effective permittivity of the substrate-air interface. The Yagi-Uda element lengths and spacings are scaled from classic free-space designs, the log-periodic array follows Carrel's design equations for the scale factor and spacing factor, and the spiral radius follows the active-region rule that the circumference equals one wavelength.

How accurate is it?

These are first-order starting geometries. Real antennas are affected by the ground-plane size, feed discontinuities, connector transitions, solder mask, nearby components and the case or human body. Expect the resonant frequency to land within about 2 to 8 percent of the target for patches and a little more for the wideband and compact types; the length scale field lets you trim the main dimension once you know the offset from a simulation or a network analyser measurement. Always verify the final design with an electromagnetic simulator or by measurement before production.

The 33 layouts you can generate

Pick any of the 33 printed antennas below, enter frequency and substrate, and the generator returns a to-scale drawing with every dimension labelled. Click a name to open it in the tool.

Patch antennas

• Rectangular patch (inset, λ/4 or probe feed): Linearly polarised microstrip patch from the transmission-line model. Choose an inset microstrip feed, an edge feed with a λ/4 transformer, or a coaxial probe through the ground plane.
• Circular patch (probe or inset feed): TM11 circular patch sized from the cavity model with fringing correction. The feed position is estimated from an assumed edge resistance, which you can tune after simulation.
• Circularly polarised patch (truncated corners): Single-feed circular polarisation: a nearly square patch with two diagonally opposite corners cut off. The cut size comes from the perturbation rule ΔS/S = 1/(2Q0); the feed sits on the patch axis, so the two orthogonal modes are excited with equal amplitude and 90° phase.
• U-slot wideband patch (probe fed): Thick-substrate patch with a U-shaped slot around the probe. The slot adds a second resonance close to the patch mode and, together with the probe inductance, widens the impedance bandwidth to 15 to 30 %. The slot length follows the half-wave rule at the air-substrate interface.
• E-shaped wideband patch: Rectangular patch with two parallel slots cut from one radiating edge. The slots lengthen the current path of one mode and so create a second, lower resonance next to the first, giving 20 to 30 % bandwidth on a moderately thick substrate.
• Gap-coupled parasitic patch (wideband): A driven rectangular patch with a second, slightly longer patch coupled across a narrow gap at its radiating edge. The two resonances sit close together and merge, which gives about twice the bandwidth of a single patch.
• Equilateral triangular patch (probe fed): Triangular microstrip patch with the dominant TM10 mode: resonant frequency 2c / (3·a·√εr) with a fringing correction to the side length. About 70 % of the area of a square patch at the same frequency, and a good shape for arrays that must tile.
• Shorted quarter-wave patch (half-size): A rectangular patch with one radiating edge short-circuited by a row of vias. The shorted edge becomes a voltage null, so the patch is only about λg/4 long, half the area of an ordinary patch. Probe or inset microstrip feed.
• Nearly-square CP patch (probe fed on the diagonal): Single-feed circular polarisation from a patch whose two sides differ slightly. The longer side resonates a little low and the shorter a little high, so at the centre frequency the two modes are 90° apart; the probe sits on the diagonal so both are excited equally.

Patch arrays

• Linear patch array 1×N (corporate feed): Two, four or eight inset-fed patches side by side. Each patch is matched to 2·Z0; pairs are joined at T-junctions and λ/4 transformers of impedance √2·Z0 step the node impedance back up at every level.
• 2×2 patch array (centre-fed): Four patches in two rows. The feed network sits between the rows; the upper row is mirrored and its feed lines are λg/2 longer, which restores the in-phase excitation. The input line runs through the gap between the two lower patches.
• Series-fed patch array (resonant, 1×N): N identical patches in a row, joined edge to edge by narrow lines so that the centre-to-centre spacing is one guided wavelength: every patch is then excited in phase and the whole array is fed from one inset line. No power divider is needed.

Dipole and monopole

• Printed half-wave dipole: Straight strip dipole on the substrate, fed by parallel strips or by a microstrip with a bottom-layer arm. There is no ground plane under the radiator.
• Bow-tie dipole: Two triangular arms joined at the feed. A larger flare angle gives a wider impedance bandwidth than a strip dipole of the same length.
• Printed quarter-wave monopole: Straight strip monopole on a microstrip-fed board with a ground plane under the feed section only. The monopole starts at the edge of the ground plane.
• CPW-fed monopole (uniplanar): Single-layer monopole fed by a coplanar waveguide: a centre strip with a ground plane on each side, all on the top layer. The gap is solved for the feed impedance and the monopole continues past the end of the ground planes.
• Printed folded dipole: Half-wave dipole folded back on itself: two parallel strips joined at the ends, fed at the middle of one. The input resistance is about four times that of a plain dipole (near 290 Ω), which suits a 300 Ω balanced line or a 4:1 balun.
• Dual-band printed monopole (two-strip): Two quarter-wave strips of different lengths fed from a common point over a partial ground plane: the long strip sets the lower band and the short strip the upper band. The band ratio is a free choice.

Compact and meandered

• Meander-line monopole: A quarter-wave monopole folded into a meander to fit a small board. Choose the amplitude and pitch of the meander; the number of turns is solved from the target length.
• Inverted-F antenna (PCB IFA): Compact PCB antenna at the board edge: a horizontal radiating arm, a shorting stub to ground through a via, and a microstrip feed stub a few millimetres away.
• Planar inverted-F antenna (PIFA): Rectangular plate over a ground plane, shorted along part of one edge (a row of vias here) and fed by a probe a short distance from the short. The resonance follows L + W − Ws = λ/4 (quarter-wave length of the folded path).
• Inverted-L antenna (ILA): A quarter-wave monopole bent into an L: a short vertical section above the ground edge, then a horizontal arm. It takes less height than a straight monopole. Directly microstrip-fed, with no shorting stub.
• Meandered inverted-F antenna (MIFA): An inverted-F antenna whose radiating arm is folded into a square-wave meander so that it fits a short board edge. The trace length is a quarter wavelength; the meander amplitude and pitch set the footprint.

Slot antennas

• Microstrip-fed slot antenna: A half-wave slot cut in the ground plane, fed by a microstrip on the other side that crosses the slot and ends in an open λg/4 stub.
• Annular ring slot antenna (microstrip-fed): A ring-shaped slot in the ground plane whose mean circumference is one wavelength at the slot interface. A microstrip on the other side crosses the ring and ends in an open λg/4 stub over the island.

Yagi-Uda and log-periodic

• Printed Yagi-Uda array: A driven dipole with a reflector behind it and a row of directors in front. Element lengths and spacings are scaled from classic free-space Yagi designs by the substrate εe, and the reflector is split to let the feed line pass.
• Printed log-periodic dipole array (LPDA): Two printed booms, one on each layer, with dipole halves alternately connected to each boom. The page frequency is the lowest operating frequency; set the bandwidth ratio, scale factor τ and spacing factor σ.
• Quasi-Yagi (microstrip-fed, end-fire): Printed end-fire antenna: a microstrip-fed dipole driver, one to three director dipoles and the truncated ground-plane edge acting as the reflector. One arm of the driver is on the top layer, the other on the bottom layer, joined to the ground plane through a narrow return strip.

Loop and spiral

• Printed loop (resonant or small + capacitor): Circular or square loop with a feed gap. A resonant loop has a circumference of about one wavelength; a small loop is resonated by a series capacitor placed opposite the feed.
• Archimedean spiral antenna (2-arm, circularly polarised): Two interleaved Archimedean arms wound 180° apart, fed in the centre. The outer radius sets the lowest frequency and the inner radius the highest; the arm width is a fraction of the winding pitch.

Wideband planar

• Planar disc or elliptical monopole (UWB): A disc or ellipse fed by a microstrip over a partial ground plane. The size follows a quarter-wave rule for the lowest frequency; a small gap between the disc and the ground edge gives the very wide bandwidth.
• Antipodal Vivaldi antenna: Exponential tapered-slot antenna on a double-sided board. The microstrip on the top layer feeds the upper flare and a ground strip on the bottom layer feeds the lower flare; the two flares open into the aperture.
• Beveled rectangular planar monopole (UWB): A rectangular plate with the lower corners cut at 45°, fed by a microstrip over a partial ground plane with a small gap. The bevel smooths the transition from the feed line to the plate and widens the impedance bandwidth, giving an ultra-wideband antenna.

Frequently asked questions

What does the printed antenna layout generator do?

It takes your design frequency and substrate (relative permittivity, loss tangent, height, copper thickness), applies the design equations for the chosen antenna and draws the copper shapes to scale with every length and width labelled, including the microstrip feed line sized for 50 ohms.

Which antennas are included?

Rectangular, circular, circularly polarised, triangular, U-slot, E-shaped, gap-coupled, shorted-wall and nearly-square patches, ring slot, parallel and series-fed patch arrays, dipoles, folded dipole, monopoles (CPW, dual-band, beveled), inverted-L, inverted-F and PIFA, meander and slot antennas, Yagi-Uda, quasi-Yagi, log-periodic arrays, loops, spirals, disc monopoles and Vivaldi antennas.

Can I export the antenna for PCB fabrication or simulation?

Yes. Each design exports as SVG, DXF for CAD and EM solvers, and Gerber layers for the board house. A mil display mode is available.

How accurate is the resonant frequency?

Expect the resonance to land within about 2 to 8 percent of target for patches and a little more for wideband and compact types. Use the length scale field to trim after a simulation or network-analyser measurement, and always verify the final design.

Is it free?

Yes. It runs in your browser, needs no sign-up and nothing you type is uploaded.