Antenna tilt calculator

1. Method [1]
If the sites are located in the flat/semi-flat areas, we should
neglect the terrain height.
Variable Definitions:
ha is the antenna height for cell A
hb is the antenna height for cell B
Ga is the ground height at cell A
Gb is the ground height at cell B
da is the distance cell A dominance should extend after the
down tilt
db is the distance cell B dominance should extend after the
down tilt
GbGa
ha
hb
da
dbda
db
D
Sea level
Cell BoundaryCell Boundary
CELL “A” CELL “B”
◄ Figure 1.1 Trigonometry with Cell Boundary ►
Assume that cell “A” antenna has β electrical down tilt and δ
mechanical down tilt. From the following figure the antenna tilt
required is
)(tan 1
a
a
a
d
h−
=θ

2. ha
da
θ a
CELL “A”
(β + δ )
◄ Figure 1.2 Trigonometry ►
Cell Boundary
Ga = Gb Cell Boundary
Gb
Ga
CELL “A” CELL “B”
CELL “A”
CELL “B”
Cell Boundary
Ga = Gb Cell Boundary
Gb
Ga
CELL “A” CELL “B”
CELL “A”
CELL “B”
◄ Figure 1.3 Method [1] can be applied in Flat/Semi-flat
Area ►

3. Method [2]
If the sites are located in the hilly areas, we should consider
the terrain height.
Variable Definitions:
ha is the antenna height for cell A
hb is the antenna height for cell B
Ga is the ground height at cell A
Gb is the ground height at cell B
Gc is the ground height at cell dominance boundary
da is the distance cell A dominance should extend after the
down tilt
db is the distance cell B dominance should extend after the
down tilt
Gb
Ga
ha
hb
da
db
D
Sea level
Gc Cell Boundary
CELL “A” CELL “B”
Gb
Ga
ha
hb
da
dbda
db
D
Sea level
GcGc Cell BoundaryCell Boundary
CELL “A” CELL “B”
◄ Figure 2.1 Trigonometry with Cell Boundary ►
Assume that cell “A” antenna has β electrical down tilt and δ
mechanical down tilt. From the following figure the antenna tilt
required is
)
)(
(tan 1
a
caa
a
d
GGh −+
= −
θ

4. ha
Ga- Gc
ha+ (Ga - Gc)
da
θ a
CELL “A”
(β + δ )
ha
Ga- Gc
ha+ (Ga - Gc)
da
θ a
CELL “A”
(β + δ )
◄ Figure 2.2 Trigonometry ►
In the hilly area, the ground height at the cell boundary should
be considered. Ground height at the cell boundary (Gc) is
higher/lower than Ga and Gb.
Gc
Gb
Ga
Cell Boundary
CELL “B”
Cell Boundary
Gb
Ga
CELL “A”
CELL “B”
Gc
CELL “A”
◄ Figure 2.3 Method [2] can be applied in Hilly Area ►
 Calculation Formula with Electrical and Mechanical Tilt
Assume that cell “A” antenna has β electrical down tilt and δ
mechanical down tilt.
β
θ
−
−+
=
−=
−
)
)(
(tan 1
a
caa
d
GGh
ltectricalTiExistingElcalTiltNewMechani
βδ
θ
−−
−+
=
−−=
−
)
)(
(tan 1
a
caa
d
GGh
ltectricalTiExistingElltchanicalTiExistingMecalTiltAddMechani