Ubuntu 18.04 No WiFi adapter found [Dell Inspiron 3542.]

Just installed Ubuntu 18.04 but my WiFi adapter Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter doesn't work or even appear in the system settings.

output of lspci -knn | grep Net -A3:

> rahul@rahul-Inspiron-3542:~$ lspci -knn | grep Net -A3
06:00.0 Network controller [0280]: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter [168c:0036] (rev 01)
    Subsystem: Dell QCA9565 / AR9565 Wireless Network Adapter [1028:020c]
    Kernel driver in use: ath9k
    Kernel modules: ath9k
07:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller [10ec:8136] (rev 07)

output of lspci -knn | grep Net -A2

rahul@rahul-Inspiron-3542:~$ lspci -knn | grep Net -A2
06:00.0 Network controller [0280]: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter [168c:0036] (rev 01)
    Subsystem: Dell QCA9565 / AR9565 Wireless Network Adapter [1028:020c]
    Kernel driver in use: ath9k
    Kernel modules: ath9k

output of sudo rfkill list

rahul@rahul-Inspiron-3542:~$ sudo rfkill list
[sudo] password for rahul: 
0: dell-rbtn: Wireless LAN
    Soft blocked: yes
    Hard blocked: yes
1: phy0: Wireless LAN
    Soft blocked: no
    Hard blocked: no
2: hci0: Bluetooth
    Soft blocked: yes
    Hard blocked: no

output of sudo lshw -C network

rahul@rahul-Inspiron-3542:~$ sudo lshw -C network
  *-network DISABLED        
       description: Wireless interface
       product: QCA9565 / AR9565 Wireless Network Adapter
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:06:00.0
       logical name: wlp6s0
       version: 01
       serial: 4c:bb:58:30:aa:07
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical wireless
       configuration: broadcast=yes driver=ath9k driverversion=4.17.11-041711-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11
       resources: irq:18 memory:f7900000-f797ffff memory:f7980000-f798ffff
  *-network
       description: Ethernet interface
       product: RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:07:00.0
       logical name: enp7s0
       version: 07
       serial: 74:e6:e2:14:2a:c8
       size: 10Mbit/s
       capacity: 100Mbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl8106e-1_0.0.1 06/29/12 latency=0 link=no multicast=yes port=MII speed=10Mbit/s
       resources: irq:19 ioport:e000(size=256) memory:f7800000-f7800fff memory:f2100000-f2103fff
  *-network
       description: Ethernet interface
       physical id: 2
       logical name: enp0s20u1
       serial: 7a:14:5b:44:b4:96
       capabilities: ethernet physical
       configuration: broadcast=yes driver=rndis_host driverversion=22-Aug-2005 firmware=RNDIS device ip=192.168.42.109 link=yes multicast=yes

output of dmesg | grep ath9k

rahul@rahul-Inspiron-3542:~$ dmesg | grep ath9k
[   23.712505] ath9k 0000:06:00.0 wlp6s0: renamed from wlan0

output of sudo iw dev

rahul@rahul-Inspiron-3542:~$ sudo iw dev
[sudo] password for rahul: 
phy#0
    Interface wlp6s0
        ifindex 3
        wdev 0x1
        addr 4c:bb:58:30:aa:07
        type managed
        txpower 0.00 dBm

output of dmesg Output of dmesg

I already tried so many solutions but nothing works for me , I'm looking for answer from so many days. Please Someone solve my issue . If anyone want any other information please let me know.

Any help would be greatly appreciated.

Guys i tried contionusly for a month then able to find solution of problem "No WiFi adapter found " , the problem is same in all versions of ubuntu because i tried Ubuntu 16.04 and then Ubuntu 14.04 , but i finnally able to find the solution.I almost tried each and every solution available.

In my case the output of rfkill list

0: dell-rbtn: Wireless LAN
    Soft blocked: yes
    Hard blocked: yes 

so to solve the problem i need to blacklist dell-rbtn (this is hardware issue)

to balcklist dell-rbtn, i did

echo "blacklist dell-rbtn" | sudo tee /etc/modprobe.d/dell-rbtn.conf

and after this reboot the laptop and now i m able to use WIFI.

I hope this will help someone because i also tried for months to solve this problem. Thanks

One last thing my laptop configration Dell Inspiron 3542 and Network controller [0280]: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter