I am using two SXT SA5 AC for 5 km link we need 100 MBPS bandwidth for wisp backhaul link. we are getting 25 to 30 mbps bandwidth. is there special config setting for AC product.

Access point config

/interface bridge
add name=bridge1 protocol-mode=none
/interface wireless
set [ find default-name=wlan1 ] band=5ghz-a/n/ac channel-width=\
20/40/80mhz-eeeC country=austria disabled=no frequency=5240 l2mtu=1600 \
mode=ap-bridge name=wlan1-gateway nv2-preshared-key=pcpl@h2r \
nv2-security=enabled radio-name="HOME TO RANKALA" rate-set=configured \
wds-default-bridge=bridge1 wds-ignore-ssid=yes wds-mode=dynamic \
wireless-protocol=nv2
/interface ethernet
set [ find default-name=ether1 ] name=ether1-local
/ip neighbor discovery
set wlan1-gateway discover=no
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/ip pool
add name=default-dhcp ranges=192.168.88.10-192.168.88.254
/ip dhcp-server
add address-pool=default-dhcp disabled=no interface=ether1-local name=default
/interface bridge filter
add action=set-priority chain=forward new-priority=7
/interface bridge port
add bridge=bridge1 interface=ether1-local
add bridge=bridge1 interface=wlan1-gateway
/ip address
add address=192.168.245.215/24 comment="default configuration" interface=\
ether1-local network=192.168.245.0
/ip dhcp-client
add comment="default configuration" dhcp-options=hostname,clientid disabled=\
no interface=wlan1-gateway
/ip dhcp-server network
add address=192.168.88.0/24 comment="default configuration" dns-server=\
192.168.88.1 gateway=192.168.88.1
/ip dns
set allow-remote-requests=yes
/ip dns static
add address=192.168.88.1 name=router
/ip firewall filter
add chain=input comment="default configuration" connection-state=\
established,related
# in/out-interface matcher not possible when interface (wlan1-gateway) is slave - use master instead (bridge1)
add action=drop chain=input comment="default configuration" in-interface=\
wlan1-gateway
add chain=forward comment="default configuration" connection-state=\
established,related
add action=drop chain=forward comment="default configuration" \
connection-state=invalid
# in/out-interface matcher not possible when interface (wlan1-gateway) is slave - use master instead (bridge1)
add action=drop chain=forward comment="default configuration" \
connection-nat-state=!dstnat connection-state=new in-interface=\
wlan1-gateway
/ip firewall nat
add action=masquerade chain=srcnat comment="default configuration" disabled=\
yes out-interface=wlan1-gateway
/queue interface
set wlan1-gateway queue=only-hardware-queue
/system identity
set name="HOME 2 RANKALA"
/system leds
set 0 interface=wlan1-gateway
/system routerboard settings
set cpu-frequency=720MHz
/tool mac-server
set [ find default=yes ] disabled=yes
add interface=ether1-local
/tool mac-server mac-winbox
set [ find default=yes ] disabled=yes
add interface=ether1-local

Station Bridge config

/interface bridge
add name=bridge1
/interface wireless
set [ find default-name=wlan1 ] band=5ghz-a/n/ac channel-width=\
20/40/80mhz-eeeC country=austria disabled=no frequency=5240 l2mtu=1600 \
mode=station-bridge nv2-preshared-key=pcpl@h2r nv2-security=enabled \
radio-name="RANKALA TO HOME" ssid="HOME 2 RANKALA" wds-default-bridge=\
bridge1 wds-mode=dynamic wireless-protocol=nv2
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/interface bridge filter
add action=set-priority chain=forward new-priority=7
/interface bridge port
add bridge=bridge1 interface=wlan1
add bridge=bridge1 interface=ether1
/ip address
add address=192.168.245.216/24 interface=ether1 network=192.168.245.0
/ip dhcp-client
add dhcp-options=hostname,clientid interface=bridge1
/ip firewall mangle
add action=set-priority chain=output new-priority=7 protocol=icmp
/queue interface
set wlan1 queue=only-hardware-queue
/system identity
set name=RANKALA_HOME
/system routerboard settings
set cpu-frequency=720MHz

You haven't post wireless link status but anyway you had choose the wrong product for 5km and also for a backhaul link. Your signal is most likely very weak. That antenna is for sector coverage.