MMANA-GAL Antenna Modelling: Complete Ham Radio Guide
MMANA-GAL is a free, Windows-based antenna analyser built on the Method of Moments engine — the same mathematical foundation as NEC2. It is fast, accessible to beginners, and capable of accurately modelling wire antennas, Yagis, loops, verticals, and phased arrays. This guide takes you from installation through your first model to optimisation workflows used by experienced antenna designers.
MMANA-GAL was written by Makoto Mori (JE3HHT) as a Japanese antenna modelling program and later adapted and extended for international use by Igor Goncharenko (DL2KQ) and Alexander Goncharenko. It implements the Method of Moments (MoM) numerical technique, which solves Maxwell's equations for a structure of thin wire segments by computing the current distribution along each segment simultaneously. From the current distribution, MMANA derives feed point impedance, gain, radiation pattern, and efficiency.
The Method of Moments is most accurate for thin-wire antennas — dipoles, Yagis, loops, phased arrays, and similar designs where the conductor diameter is small relative to the element length. It becomes less accurate for antennas with thick elements, closely spaced parallel conductors, or complex 3D surface structures. For the vast majority of HF and VHF amateur antenna designs, MMANA-GAL produces results that agree with measured antenna performance to within 0.3–1 dB — more than sufficient for practical design work.
MMANA-GAL strengths
Fast calculation, beginner-friendly interface, free and actively maintained. Excellent for wire dipoles, Yagis, quad loops, verticals, phased arrays, and loaded antennas. Reads and writes the widely used .maa file format and can import NEC2 files.
MMANA-GAL limitations
Less accurate for thick elements (tubing) than NEC2/EZNEC. Ground modelling is simplified compared to NEC-4 with Sommerfeld-Norton ground. No transmission line modelling within the geometry. Windows only — runs under Wine on Linux/macOS.
When to use MMANA vs. alternatives
Use MMANA for quick wire antenna design, portable antenna optimisation, and HF wire arrays. Use 4NEC2 or EZNEC for more complex NEC2 geometry. Use NEC-4 for buried structures, thick elements, or when maximum accuracy is essential.
The free MMANA-GAL Basic version is available from the DL2KQ website (dl2kq.de/mmana) and several mirror sites. Download the installer package (typically mmana_setup.exe, approximately 8 MB). MMANA-GAL Pro adds batch optimisation and extended ground modelling — the Basic version is fully adequate for the workflows in this guide.
Run the installer as administrator. Accept the default installation path (C:\MMANA-GAL or similar). The installer places the executable, example antenna files (.maa), and help documentation in the install folder. No additional runtime libraries are required on Windows 7 through Windows 11.
Launch the program. Go to File → Open and navigate to the examples folder inside the installation directory. Open dipole.maa or a similar simple example. This verifies the installation is working and gives you a reference model to compare against your own work.
MMANA-GAL has four primary tabs: Geometry (wire entry), Source/Load (feed points and loads), Calculate (run the simulation), and View (radiation pattern display). The lower panel shows calculation results including impedance, SWR, gain, and efficiency in real time as you change parameters.
MMANA-GAL uses a Cartesian coordinate system: X and Y are the horizontal plane, Z is the vertical axis (height above ground). The origin (0, 0, 0) is at ground level at the centre of the antenna. Positive Z is upward; negative Z is below ground (used for buried radials). All dimensions are entered in metres.
Every antenna in MMANA is built from wire segments. Each wire is defined by its start point (X1, Y1, Z1), end point (X2, Y2, Z2), diameter in millimetres, and the number of segments to divide it into. The number of segments controls calculation accuracy — more segments per wavelength give more accurate results but take longer to calculate.
Segment count guidelines
| Application | Segments per half-wave | Notes |
|---|---|---|
| Quick check / initial design | 5–11 | Fast; adequate for resonance and impedance |
| Standard design work | 11–21 | Good balance of speed and accuracy |
| Gain / pattern accuracy | 21–51 | Better pattern accuracy, especially in sidelobes |
| Publication / verification | 51–101 | Slow; use for final design verification only |
Entering a half-wave dipole — example wire table
A 20 m band (14.2 MHz) horizontal dipole, 10 m high, using 2 mm diameter wire. Each arm is 5.05 m long:
Wire 1 runs from X = −5.05 m to X = 0 m at height Z = 10 m. Wire 2 runs from X = 0 m to X = +5.05 m at the same height. The feed point (Source) will be placed at the junction of these two wires — segment 1 of wire 2 (or segment 11 of wire 1, depending on orientation convention).
Sources, Loads & Transmission LinesPlacing the feed point (Source)
In MMANA-GAL, the feed point is defined in the Source/Load tab. Click "Add Source" and specify the wire number and segment number where the source is connected. For the dipole above, the source goes on Wire 2, Segment 1 (the segment nearest the centre). The source type is "Voltage source" with magnitude 1 V and phase 0° for standard analysis — MMANA normalises all results regardless of source voltage.
Adding loads (resistors, inductors, capacitors)
Loads model real-world components inserted into the antenna: loading coils for shortened elements, capacitors for top-loading, or resistors to simulate element conductor loss. In the Source/Load tab, click "Add Load" and specify wire, segment, and the component type and value. Common uses:
- Loading coil (inductor): Enter inductance in µH on the desired segment to shorten a vertical or dipole arm while maintaining resonance
- Loss resistance: Add a small series resistance (0.1–2 Ω) to model conductor loss in the element, providing a more realistic efficiency estimate
- Trap: Model as a series LC circuit at the trap segment — use values that resonate at the trap's design frequency
Transmission line stubs
MMANA-GAL supports transmission line elements in the Source/Load tab. A transmission line stub is defined by its characteristic impedance, electrical length in degrees, and whether it is open or short-circuit terminated. This allows accurate modelling of phased array feed systems, hairpin matches, and stub filters without needing to draw the physical transmission line geometry.
Ground Modelling in MMANA-GALGround has a profound effect on antenna performance — particularly for verticals, dipoles at low heights, and NVIS antennas. MMANA-GAL offers three ground models:
| Ground Model | Accuracy | Speed | Use When |
|---|---|---|---|
| Free space | N/A | Fastest | Comparing antenna designs in isolation; VHF/UHF where ground is far field |
| Perfect ground | Overestimates low-angle gain | Fast | Quick reference; verticals to see image current pattern |
| Real ground (MININEC) | Good for HF | Moderate | HF antennas at typical heights; realistic efficiency estimates |
For real ground, MMANA uses the MININEC ground model, which approximates the effect of finite soil conductivity and permittivity on near-field ground currents. Enter soil conductivity (σ, in S/m) and relative permittivity (εr) in the Calculate tab before running. For typical suburban installations, use σ = 0.005 S/m and εr = 13. For poor rocky ground, use σ = 0.001 and εr = 12. For good agricultural soil, use σ = 0.01 and εr = 20.
Go to the Calculate tab. Enter your operating frequency in MHz. Select the ground type and enter σ and εr if using real ground. Verify the source configuration is correct — one source with V = 1 V, phase 0°.
MMANA runs the MoM calculation and displays results almost instantly for models with under 200 segments. For larger models (phased arrays, multi-element Yagis with many segments), calculation may take 5–30 seconds. The status bar shows calculation progress.
The results panel shows feed point impedance as R + jX Ω. SWR is calculated relative to the reference impedance you set (default 50 Ω). A negative X value means the antenna is capacitively reactive (electrically short). Positive X means inductive (electrically long). Adjust wire length until X ≈ 0 for resonance.
Gain is shown in dBi (decibels relative to an isotropic radiator). MMANA also shows the take-off angle (elevation angle of the main lobe) and front-to-back ratio for directional antennas. Efficiency is shown as a percentage — values below 85% for a simple dipole suggest a modelling error or unrealistic loss loading.
Click the View tab and select 3D pattern or polar plot. The 3D pattern shows radiation in all directions simultaneously. The polar plot (2D elevation or azimuth cut) is easier to read for comparing designs. Use the azimuth plot at the take-off angle to assess directivity; use the elevation plot to assess low-angle radiation for DX.
Understanding the results panel — a typical dipole output
Inverted-V dipole
An inverted-V has its centre at maximum height and the two arms slope downward at an angle. Model it by placing the apex at height H and the wire end points lower and offset. If the arms slope at 45°, the end points are at height H − L/√2 and horizontal distance L/√2 from centre, where L is the arm length. The inverted-V presents slightly lower feed point impedance than a flat dipole (typically 50–60 Ω), varies with the included angle, and has a more omnidirectional pattern due to the vertical component of the sloping elements.
Vertical with radials
Model a quarter-wave vertical as a wire from Z = 0 to Z = λ/4 along the Z-axis. Add radial wires as horizontal spokes in the XY plane at Z = 0.01 m (slightly above ground to avoid MININEC singularities). Each radial runs from the base (0, 0, 0.01) outward to its tip. Use at least 4 radials for meaningful ground system modelling; use 8–16 for more realistic representation of a typical buried system. The source goes on the vertical element, segment 1 (bottom segment).
3-element Yagi
A Yagi consists of a reflector, driven element, and one or more directors, all parallel to each other in the Y-axis and spaced along the X-axis. Each element is a single wire centred on X = 0, Y = 0, spanning from Y = −L/2 to Y = +L/2 at the appropriate X position. The driven element has a source at its centre. Typical starting dimensions for a 3-element 20 m Yagi:
Quad loop
A full-wave quad loop can be modelled as four wire segments forming a square. For a 20 m band quad with total wire length of approximately 21.5 m, each side is 5.375 m. Place the bottom wire at height H, top wire at H + 5.375 m, and two vertical side wires connecting them. The feed point is at the centre of the bottom (or top) wire. A square quad with the feed at the bottom centre presents approximately 100–130 Ω at resonance.
The Optimiser — Automated Design RefinementMMANA-GAL's built-in optimiser is one of its most powerful features. After building an initial model, you can define a set of target parameters (desired gain, SWR, front-to-back ratio, take-off angle) and a set of variable parameters (wire lengths, element spacings, heights), and let the optimiser search for the combination that best meets your targets.
Setting up the optimiser
The optimiser refines an existing model — it does not design from scratch. Start with a model close to your desired design (within 10–20% of final dimensions) so the optimiser searches efficiently rather than exploring wildly different geometries.
In the Geometry tab, right-click on wire end coordinates and select "Set as variable." Define the allowed range (minimum and maximum values) for each variable. For a Yagi, you might vary each element length ±10% and element spacing ±20% around the starting values.
In the Optimise tab, set targets: maximum gain, minimum SWR at the design frequency, minimum front-to-back ratio, and any band edge SWR constraints. Assign weights to each target — a weight of 10 for SWR makes the optimiser prioritise matching over a minor gain improvement.
Click Start Optimisation. MMANA runs hundreds or thousands of calculations, each slightly varying the parameters and evaluating the merit function. Watch the progress — if the optimiser converges quickly to a poor local minimum, stop it, adjust the starting model, and try again. A good optimisation run typically finds meaningful improvements within 2–5 minutes.
After optimisation, re-run the calculation manually and check all results: impedance, SWR across the band, gain, pattern, and efficiency. Optimisers sometimes find mathematically valid solutions that are physically unrealisable or impractical — check that element lengths and spacings are buildable and that no wires are unrealistically thin or excessively close together.
Wire Segment Count & Coordinate Generator
555;margin-bottom:14px;font-family:Arial,sans-serif">Generates correct segment counts and start/end coordinates for common antenna types, ready to enter into MMANA-GAL.
Wires not connected
In MMANA, wires are connected when their endpoints share exactly the same coordinates. A mismatch of even 0.001 m means the wires are not electrically connected — current cannot flow between them. Always use copy-paste to transfer junction coordinates between wires rather than retyping, and verify junction coordinates match exactly. Use the Check Geometry function (under the Geometry menu) to identify unconnected wire ends before running a calculation.
Segments too long or too short
Segments longer than 0.1λ produce poor results because the MoM piecewise approximation breaks down. Segments shorter than 0.001λ cause numerical instability. A common error is using the same segment count for both a full-length Yagi boom and a short loading coil — the boom segments may be 0.05λ (fine) while the coil wire segments are 0.0001λ (too short). Match segment length across the model by setting segment counts proportional to wire length.
Source on the wrong segment
Placing the source on the wrong segment shifts the feed point off-centre, making the impedance appear wrong and the radiation pattern asymmetric. For a centre-fed dipole, the source should be on segment 1 of the second half-wire or segment N of the first half-wire — the segment immediately adjacent to the physical centre. Verify by running the model and checking that the gain pattern is symmetric.
Ignoring ground effects for low-mounted antennas
Free-space or perfect-ground simulations look good but can be misleading for antennas mounted below 0.3λ. Run all practical HF antenna models with a real ground (σ and εr appropriate for your site) to get realistic efficiency and pattern estimates. The difference between perfect ground and average real ground can be 2–4 dB in low-angle gain for a dipole at 0.25λ height.
Diameter changes at junctions (NEC limitation)
NEC2 (and MMANA's MoM engine) assumes that connected wires at a junction are all the same diameter, or introduces modelling errors if they differ greatly. Where element diameter changes along an antenna (e.g., a tapered aluminium Yagi element stepped from 25 mm to 19 mm to 12 mm), use the Leeson correction or model the taper as a series of uniform-diameter sections with matching junction segment lengths. MMANA's Pro version includes a stepped-diameter correction function.
Typical MMANA Results for Reference Antennas| Antenna | Band | Height | Gain (dBi) | TO angle | Feed Z (Ω) | SWR (50Ω) |
|---|---|---|---|---|---|---|
| Half-wave dipole | 20m | 10m (0.47λ) | 7.8 | 30° | 67 + j2 | 1.35 |
| Half-wave dipole | 40m | 10m (0.24λ) | 6.3 | 56° | 55 + j8 | 1.18 |
| Inverted-V (120° incl.) | 40m | 12m apex | 5.9 | 58° | 52 + j4 | 1.08 |
| Vertical + 4 radials | 40m | Ground level | 1.2 | 25° | 42 + j5 | 1.25 |
| Vertical + 32 radials | 40m | Ground level | 2.8 | 23° | 36 + j2 | 1.44 |
| 3-el Yagi | 20m | 12m boom | 14.2 | 16° | 28 + j10 | 2.0 |
| 3-el Yagi + gamma match | 20m | 12m boom | 14.2 | 16° | 50 + j2 | 1.04 |
| Full-wave square loop | 20m | 10m (bottom) | 8.4 | 27° | 110 + j15 | 2.3 |
How accurate is MMANA-GAL compared to a real antenna?
For wire antennas in free space or over real ground at HF, MMANA typically predicts resonant frequency within 1–2%, feed point impedance within 5–10%, and gain within 0.3–1 dB of measured values. Accuracy degrades for thick-element antennas (tubing), antennas very close to ground, or antennas near complex structures not included in the model.
What is the difference between MMANA-GAL and 4NEC2?
Both use the NEC2 Method of Moments engine but with different interfaces. MMANA is faster to learn and better for quick wire antenna work. 4NEC2 provides a full NEC2 input file editor, more ground model options, frequency sweeps, and better handling of thick elements via its stepped-diameter correction. For most HF wire antenna work, either tool gives equivalent results.
Can MMANA-GAL model a phased vertical array?
Yes. Model each vertical element and its radial system as separate wire groups, then add transmission line elements in the Source/Load tab to represent the phasing network. Multiple sources can be placed on different elements with different phase angles. MMANA accurately models the mutual coupling between phased elements that changes the individual element impedances from their self-impedance values.
My gain shows negative dBi — is something wrong?
Not necessarily. Gain in dBi is relative to a theoretical isotropic radiator. A short, inefficient antenna can have negative dBi gain — it radiates less than an isotropic source would in the same direction. A short loaded vertical on 160 m might show −2 to −5 dBi gain, meaning poor efficiency rather than a modelling error. Check the efficiency percentage — values below 50% on a simple wire antenna suggest either a very short element or excessive loss loading.
How do I model a balun in MMANA-GAL?
A 1:1 current balun is modelled as a common-mode choke — its effect on the antenna model is to prevent current flow on the outer conductor of the coax, which is achieved in MMANA by simply not extending the source wire beyond the feed point. A voltage balun or impedance-transforming balun is modelled as a transmission line transformer in the Source/Load tab with the appropriate impedance ratio specified.
Can I import NEC files into MMANA-GAL?
Yes. MMANA-GAL Basic can import NEC2-format input files (.nec) with some limitations — complex NEC2 cards such as LD (distributed loads), TL (transmission lines), and NT (network) are partially supported. The geometry (GW cards) and source (EX cards) import reliably. Files exported from EZNEC and 4NEC2 import into MMANA correctly for most common antenna types.