Antenna Guide
A concise introduction to the world of antennas. Whether you spotted something on a rooftop and want to know what it is, or you're just getting into the hobby — start here.
Cell Tower Antennas
The most common antennas you'll see. Tall lattice or monopole towers with rectangular panel antennas mounted at the top. Each panel covers a sector (typically 120 degrees). Modern towers carry equipment for multiple carriers and technologies — 4G LTE, 5G NR, and sometimes legacy 3G.
What to look for:
- Panel antennas — Rectangular boxes (2-6 feet tall), usually in groups of 3 covering 360 degrees
- Small cells — Compact units on utility poles or streetlights, often mistaken for surveillance equipment
- 5G mmWave — Small, square panels angled toward streets, much shorter range than traditional towers
- Remote radio heads (RRH) — Equipment boxes mounted near the antennas rather than at the base
Satellite Dishes
Parabolic reflectors that focus signals to/from satellites. Size matters — a larger dish captures more signal. You'll see everything from small home TV dishes (45-90cm) to massive earth station dishes (3-30 meters).
Common types:
- Direct-to-home TV — Small offset dishes (DirecTV, Dish Network, Sky)
- VSAT — Medium dishes (1-2m) for business internet, often on rooftops
- Earth stations — Large dishes (3m+) at teleport facilities
- Starlink — Flat phased-array panel (no traditional dish shape), the "Dishy McFlatface"
Ham Radio / Amateur Radio
Amateur radio operators ("hams") use a wide variety of antennas depending on frequency band and purpose. This is where antenna design gets creative.
Common ham antennas:
- Yagi-Uda — Directional, looks like a TV antenna with parallel elements. Used for VHF/UHF and satellite work
- Dipole — The simplest antenna: a wire cut to half wavelength, fed in the center. Often strung between trees or hung from masts
- Vertical — A single pole or whip, ground-mounted or roof-mounted. Omnidirectional pattern
- Wire antennas — Long wire, end-fed, G5RV, random wire. Cheap, effective, often invisible
- Loop antennas — Magnetic loops (small, indoor-friendly) or full-wave loops (large, outdoor)
- Beam antennas — Multi-element directional antennas on rotators for DX (long-distance) contacts
Broadcast Antennas
The big ones. FM radio and TV broadcast antennas sit atop tall towers and pump out kilowatts of power.
- FM broadcast — Circular arrays of dipoles or ring antennas near the top of towers
- TV (UHF) — Panel antennas or slotted cylinder antennas
- AM radio — The tower itself IS the antenna. Those tall, thin, guyed towers with red lights are AM broadcast towers, insulated from the ground
Microwave / Point-to-Point
Round dishes (0.3-3m) that create focused beams between two fixed points. Used by telecom companies, utilities, and broadcasters to backhaul data between towers.
- Parabolic dishes — Round, with a protective radome (cover). Usually paired — one on each end
- Flat panel — Newer designs for short-range links
- Horn antennas — Flared metal horns, used in specialized applications
Military / Radar
Military antennas range from tactical field antennas to massive phased-array radar installations.
- Phased array radar — Flat panels with hundreds/thousands of elements. Can steer the beam electronically without moving. AEGIS, THAAD, Patriot
- Rotating radar — The classic spinning dish on airports and ships (ATC, weather, military surveillance)
- SIGINT/ELINT — Large domes (radomes) hiding the actual antenna shape for secrecy. Often at listening posts
- HF whips — Long, flexible whip antennas on military vehicles
- Satellite ground terminals — Large dishes at military bases for SATCOM
Emergency / Public Safety
- Repeater sites — VHF/UHF antennas on hilltops and buildings for police, fire, EMS radio
- P25 digital — Same towers but digital trunked systems
- FirstNet — Dedicated LTE network for first responders, often co-located on existing cell towers
IoT & Smart City
- LoRa gateways — Small antennas for long-range, low-power IoT sensors
- Mesh network nodes — Small boxes on poles for municipal WiFi or smart city applications
- Smart meters — Built-in antennas in utility meters for automated reading
Quick Identification Tips
- Rectangular panels in groups of 3 = cell tower
- Round dish pointed at the sky = satellite
- Round dish pointed at the horizon = microwave point-to-point
- Parallel horizontal elements on a boom = yagi
- Tall thin tower with red lights, no visible antennas = AM broadcast (the tower is the antenna)
- Spinning dish = radar
- White dome hiding the antenna = radome (usually military, radar, or satellite)
- Small box on a utility pole = small cell or IoT gateway
Frequency Bands (Quick Reference)
| Band | Frequency | Common Use |
|---|
| HF | 3-30 MHz | Ham radio, shortwave, military |
| VHF | 30-300 MHz | FM radio, TV, ham, marine, aviation |
| UHF | 300 MHz-3 GHz | TV, cell phones (4G/5G), ham, public safety |
| SHF | 3-30 GHz | Satellite, radar, microwave links, 5G mmWave |
| EHF | 30-300 GHz | Military, research, emerging 5G/6G |