All Advertisemetns

// WP_Query arguments
$args = array(
	'name'                   => 'ad',
	'post_type'              => array( 'ad' ),
	'post_status'            => array( 'publish' ),
	'has_password'           => false,
	'nopaging'               => false,
	'posts_per_page'         => '20',
	'posts_per_archive_page' => '20',
	'ignore_sticky_posts'    => false,
	'order'                  => 'DESC',
	'orderby'                => 'date',
);

// The Query
$query_all_advertisements = new WP_Query( $args );

// The Loop
if ( $query_all_advertisements->have_posts() ) {
	while ( $query_all_advertisements->have_posts() ) {
		$query_all_advertisements->the_post();
		// do something
	}
} else {
	// no posts found
}

// Restore original Post Data
wp_reset_postdata();